From 1dfec99d7a0b6299a4c639b99d4c097872b03c9f Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 02:34:56 +0200
Subject: [PATCH 01/13] .

---
 .../src/mill/bsp/worker/MillBuildServer.scala |  2 +-
 bsp/worker/src/mill/bsp/worker/Utils.scala    |  2 +-
 .../mill/contrib/buildinfo/BuildInfo.scala    |  2 +-
 .../src/mill/playlib/RouterModule.scala       |  3 +-
 .../playlib/src/mill/playlib/Version.scala    |  4 +-
 .../src/mill/playlib/PlayModuleTests.scala    |  3 +-
 .../src/mill/playlib/RouterModuleTests.scala  |  4 +-
 .../api/ScoverageReportWorkerApi.scala        | 46 ---------
 .../api/ScoverageReportWorkerApi2.java        | 95 +++++++++++++++++++
 .../contrib/scoverage/ScoverageModule.scala   |  2 +-
 .../contrib/scoverage/ScoverageReport.scala   |  2 +-
 .../scoverage/ScoverageReportWorker.scala     | 65 +++++++++++--
 .../worker/ScoverageReportWorkerImpl.scala    | 32 ++++---
 .../src/mill/twirllib/TwirlModule.scala       |  4 +-
 .../src/mill/twirllib/HelloWorldTests.scala   | 13 ++-
 example/thirdparty/mockito/build.mill         | 14 +++
 example/thirdparty/netty/build.mill           |  4 +-
 .../mill-build/mill-build/build.mill          |  2 +-
 .../src/MultiLevelBuildTests.scala            | 44 ++++-----
 19 files changed, 233 insertions(+), 110 deletions(-)
 delete mode 100644 contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi.scala
 create mode 100644 contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java

diff --git a/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala b/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
index 727be75c932c..23ec8ca7d398 100644
--- a/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
+++ b/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
@@ -632,7 +632,7 @@ private class MillBuildServer(
       State
   ) => V): CompletableFuture[V] = {
     val prefix = hint.split(" ").head
-    completable(hint) { state: State =>
+    completable(hint) { (state: State) =>
       val ids = state.filterNonSynthetic(targetIds(state).asJava).asScala
       val tasksSeq = ids.flatMap { id =>
         val (m, ev) = state.bspModulesById(id)
diff --git a/bsp/worker/src/mill/bsp/worker/Utils.scala b/bsp/worker/src/mill/bsp/worker/Utils.scala
index 5fe3f57b1900..7b96c76a88ea 100644
--- a/bsp/worker/src/mill/bsp/worker/Utils.scala
+++ b/bsp/worker/src/mill/bsp/worker/Utils.scala
@@ -34,7 +34,7 @@ private object Utils {
       originId: String,
       bspIdsByModule: Map[BspModule, BuildTargetIdentifier],
       client: BuildClient
-  ): Int => Option[CompileProblemReporter] = { moduleHashCode: Int =>
+  ): Int => Option[CompileProblemReporter] = { (moduleHashCode: Int) =>
     bspIdsByModule.find(_._1.hashCode == moduleHashCode).map {
       case (module: JavaModule, targetId) =>
         val buildTarget = module.bspBuildTarget
diff --git a/contrib/buildinfo/src/mill/contrib/buildinfo/BuildInfo.scala b/contrib/buildinfo/src/mill/contrib/buildinfo/BuildInfo.scala
index 2f83bc600503..dcd6f0d8bcee 100644
--- a/contrib/buildinfo/src/mill/contrib/buildinfo/BuildInfo.scala
+++ b/contrib/buildinfo/src/mill/contrib/buildinfo/BuildInfo.scala
@@ -173,7 +173,7 @@ object BuildInfo {
          |package ${buildInfoPackageName}
          |
          |object $buildInfoObjectName {
-         |  private[this] val buildInfoProperties: java.util.Properties = new java.util.Properties()
+         |  private val buildInfoProperties: java.util.Properties = new java.util.Properties()
          |
          |  {
          |    val buildInfoInputStream = getClass
diff --git a/contrib/playlib/src/mill/playlib/RouterModule.scala b/contrib/playlib/src/mill/playlib/RouterModule.scala
index fdfeaa2605f4..67123db1df07 100644
--- a/contrib/playlib/src/mill/playlib/RouterModule.scala
+++ b/contrib/playlib/src/mill/playlib/RouterModule.scala
@@ -80,7 +80,8 @@ trait RouterModule extends ScalaModule with Version {
       repositoriesTask(),
       artifactSuffix = playMinorVersion() match {
         case "2.6" => "_2.12"
-        case _ => "_2.13"
+        case "2.7" | "2.8" => "_2.13"
+        case _ => "_3"
       }
     )
   }
diff --git a/contrib/playlib/src/mill/playlib/Version.scala b/contrib/playlib/src/mill/playlib/Version.scala
index c129d3820cf4..a9640fac8eea 100644
--- a/contrib/playlib/src/mill/playlib/Version.scala
+++ b/contrib/playlib/src/mill/playlib/Version.scala
@@ -12,11 +12,11 @@ private[playlib] trait Version extends Module {
     playVersion().split('.').take(2).mkString(".")
   }
 
-  private[playlib] def playOrganization: T[String] = Task.Anon {
+  private[playlib] def playOrganization: Task[String] = Task.Anon {
     if (playVersion().startsWith("2.")) "com.typesafe.play" else "org.playframework"
   }
 
-  private[playlib] def component(id: String) = Task.Anon {
+  private[playlib] def component(id: String): Task[Dep] = Task.Anon {
     ivy"${playOrganization()}::$id::${playVersion()}"
   }
 }
diff --git a/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala b/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala
index afd219fcd7c6..a6a97db4d6fc 100644
--- a/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala
+++ b/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala
@@ -1,6 +1,7 @@
 package mill
 package playlib
 
+import mill.scalalib.api.ZincWorkerUtil
 import mill.testkit.{TestBaseModule, UnitTester}
 import utest.{TestSuite, Tests, assert, _}
 
@@ -102,7 +103,7 @@ object PlayModuleTests extends TestSuite with PlayTestSuite {
               os.RelPath("controllers/routes$javascript.class"),
               os.RelPath("controllers/javascript/ReverseHomeController.class"),
               os.RelPath("controllers/javascript/ReverseAssets.class"),
-              if (scalaVersion.startsWith("3.")) os.RelPath("router/Routes$$anon$1.class")
+              if (ZincWorkerUtil.isScala3(scalaVersion)) os.RelPath("router/Routes$$anon$1.class")
               else os.RelPath("router/Routes$$anonfun$routes$1.class"),
               os.RelPath("router/Routes.class"),
               os.RelPath("router/RoutesPrefix$.class"),
diff --git a/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala b/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
index 718ddf27670e..c50199b2f862 100644
--- a/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
+++ b/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
@@ -71,7 +71,7 @@ object RouterModuleTests extends TestSuite with PlayTestSuite {
             val eitherResult = eval.apply(project.compileRouter)
             val Left(Failure(message, x)) = eitherResult
             val playExpectedMessage =
-              if (playVersion.startsWith("2.6.")) {
+              if (!playVersion.startsWith("2.7.") && !playVersion.startsWith("2.8.")) {
                 "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
               } else {
                 "end of input expected"
@@ -98,7 +98,7 @@ object RouterModuleTests extends TestSuite with PlayTestSuite {
             val eitherResult = eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
             val Left(Failure(message, x)) = eitherResult
             val playExpectedMessage =
-              if (playVersion.startsWith("2.6.")) {
+              if (!playVersion.startsWith("2.7.") && !playVersion.startsWith("2.8.")) {
                 "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
               } else {
                 "end of input expected"
diff --git a/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi.scala b/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi.scala
deleted file mode 100644
index 55fc01d3dc78..000000000000
--- a/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi.scala
+++ /dev/null
@@ -1,46 +0,0 @@
-package mill.contrib.scoverage.api
-
-import mill.api.Ctx
-
-trait ScoverageReportWorkerApi {
-  import ScoverageReportWorkerApi._
-
-  @deprecated("Use other overload instead.", "Mill after 0.10.7")
-  def report(
-      reportType: ReportType,
-      sources: Seq[os.Path],
-      dataDirs: Seq[os.Path]
-  )(implicit
-      ctx: Ctx
-  ): Unit = {
-    report(reportType, sources, dataDirs, ctx.workspace)
-  }
-
-  def report(
-      reportType: ReportType,
-      sources: Seq[os.Path],
-      dataDirs: Seq[os.Path],
-      sourceRoot: os.Path
-  )(implicit
-      ctx: Ctx
-  ): Unit = {
-    // FIXME: We only call the deprecated version here, to preserve binary compatibility. Remove when appropriate.
-    ctx.log.error(
-      "Binary compatibility stub may cause infinite loops with StackOverflowError. You need to implement: def report(ReportType, Seq[Path], Seq[Path], os.Path): Unit"
-    )
-    report(reportType, sources, dataDirs)
-  }
-}
-
-object ScoverageReportWorkerApi {
-  sealed trait ReportType
-  sealed trait FileReportType extends ReportType { def folderName: String }
-  object ReportType {
-    final case object Html extends FileReportType { val folderName: String = "htmlReport" }
-    final case object Xml extends FileReportType { val folderName: String = "xmlReport" }
-    final case object XmlCobertura extends FileReportType {
-      val folderName: String = "xmlCoberturaReport"
-    }
-    final case object Console extends ReportType
-  }
-}
diff --git a/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java b/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java
new file mode 100644
index 000000000000..09868af8b3e1
--- /dev/null
+++ b/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java
@@ -0,0 +1,95 @@
+package mill.contrib.scoverage.api;
+
+import java.nio.file.Path;
+import java.nio.file.Files;
+import java.io.IOException;
+import java.io.Serializable;
+
+public interface ScoverageReportWorkerApi2 {
+
+  interface Logger {
+    void info(String msg);
+    void error(String msg);
+    void debug(String msg);
+  }
+
+  interface Ctx {
+    Logger log();
+    Path dest();
+  }
+
+  public static abstract class ReportType implements Serializable {
+    private String name;
+
+    /*private[api]*/
+    ReportType(String name) {}
+
+    public static final ReportType Console = new ConsoleModule();
+    public static final FileReportType Html = new HtmlModule();
+    public static final FileReportType Xml = new XmlModule();
+    public static final FileReportType XmlCobertura = new XmlCoberturaModule();
+
+    /* private[api]*/
+    static final class ConsoleModule extends ReportType implements Serializable {
+      /* private[api]*/
+      ConsoleModule() {
+        super("Console");
+      }
+    };
+
+    /* private[api]*/
+    static final class HtmlModule extends FileReportType implements Serializable {
+      /* private[api]*/
+      HtmlModule() {
+        super("Html", "htmlReport");
+      }
+    };
+
+    /* private[api]*/
+    static final class XmlModule extends FileReportType implements Serializable {
+      /* private[api]*/
+      XmlModule() {
+        super("Xml", "xmlReport");
+      }
+    }
+
+    /* private[api]*/
+    static final class XmlCoberturaModule extends FileReportType implements Serializable {
+      /* private[api]*/
+      XmlCoberturaModule() {
+        super("XmlCobertura", "xmlCoberturaReport");
+      }
+    }
+
+    @Override
+    public String toString() {
+      return name;
+    }
+  }
+
+  public static abstract class FileReportType extends ReportType implements Serializable {
+    private final String folderName;
+
+    /*private[api]*/
+    FileReportType(String name, String folderName) {
+      super(name);
+      this.folderName = folderName;
+    }
+
+    public String folderName() {
+      return folderName;
+    }
+  }
+
+  void report(ReportType reportType, Path[] sources, Path[] dataDirs, Path sourceRoot, Ctx ctx);
+
+  static void makeAllDirs(Path path) throws IOException {
+    // Replicate behavior of `os.makeDir.all(path)`
+    if (Files.isDirectory(path) && Files.isSymbolicLink(path)) {
+      // do nothing
+    } else {
+      Files.createDirectories(path);
+    }
+  }
+
+}
diff --git a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageModule.scala b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageModule.scala
index fba21cb2ccd2..e7824a266b04 100644
--- a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageModule.scala
+++ b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageModule.scala
@@ -3,7 +3,7 @@ package mill.contrib.scoverage
 import coursier.Repository
 import mill._
 import mill.api.{Loose, PathRef, Result}
-import mill.contrib.scoverage.api.ScoverageReportWorkerApi.ReportType
+import mill.contrib.scoverage.api.ScoverageReportWorkerApi2.ReportType
 import mill.main.BuildInfo
 import mill.scalalib.api.ZincWorkerUtil
 import mill.scalalib.{Dep, DepSyntax, JavaModule, ScalaModule}
diff --git a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReport.scala b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReport.scala
index fd25e64e3daf..e7c6ed5670f9 100644
--- a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReport.scala
+++ b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReport.scala
@@ -1,6 +1,6 @@
 package mill.contrib.scoverage
 
-import mill.contrib.scoverage.api.ScoverageReportWorkerApi.ReportType
+import mill.contrib.scoverage.api.ScoverageReportWorkerApi2.ReportType
 import mill.define.{Command, Module, Task}
 import mill.eval.Evaluator
 import mill.resolve.{Resolve, SelectMode}
diff --git a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala
index 799ed317178c..600c90d3bb92 100644
--- a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala
+++ b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala
@@ -2,13 +2,18 @@ package mill.contrib.scoverage
 
 import mill.{Agg, Task}
 import mill.api.{ClassLoader, Ctx, PathRef}
-import mill.contrib.scoverage.api.ScoverageReportWorkerApi
+import mill.contrib.scoverage.api.ScoverageReportWorkerApi2
 import mill.define.{Discover, ExternalModule, Worker}
 
+import ScoverageReportWorker.ScoverageReportWorkerApiBridge
+import ScoverageReportWorkerApi2.ReportType
+import ScoverageReportWorkerApi2.{Logger => ApiLogger}
+import ScoverageReportWorkerApi2.{Ctx => ApiCtx}
+
 class ScoverageReportWorker extends AutoCloseable {
-  private[this] var scoverageClCache = Option.empty[(Long, ClassLoader)]
+  private var scoverageClCache = Option.empty[(Long, ClassLoader)]
 
-  def bridge(classpath: Agg[PathRef])(implicit ctx: Ctx): ScoverageReportWorkerApi = {
+  def bridge(classpath: Agg[PathRef])(implicit ctx: Ctx): ScoverageReportWorkerApiBridge = {
 
     val classloaderSig = classpath.hashCode
     val cl = scoverageClCache match {
@@ -24,11 +29,43 @@ class ScoverageReportWorker extends AutoCloseable {
         cl
     }
 
-    cl
-      .loadClass("mill.contrib.scoverage.worker.ScoverageReportWorkerImpl")
-      .getDeclaredConstructor()
-      .newInstance()
-      .asInstanceOf[api.ScoverageReportWorkerApi]
+    val worker =
+      cl
+        .loadClass("mill.contrib.scoverage.worker.ScoverageReportWorkerImpl")
+        .getDeclaredConstructor()
+        .newInstance()
+        .asInstanceOf[api.ScoverageReportWorkerApi2]
+
+    def ctx0(implicit ctx: Ctx): ApiCtx = {
+      val logger = new ApiLogger {
+        def info(msg: String): Unit = ctx.log.info(msg)
+        def error(msg: String): Unit = ctx.log.error(msg)
+        def debug(msg: String): Unit = ctx.log.debug(msg)
+      }
+      new ApiCtx {
+        def log() = logger
+        def dest() = ctx.dest.toNIO
+      }
+    }
+
+    new ScoverageReportWorkerApiBridge {
+      override def report(
+          reportType: ReportType,
+          sources: Seq[os.Path],
+          dataDirs: Seq[os.Path],
+          sourceRoot: os.Path
+      )(implicit
+          ctx: Ctx
+      ): Unit = {
+        worker.report(
+          reportType,
+          sources.map(_.toNIO).toArray,
+          dataDirs.map(_.toNIO).toArray,
+          sourceRoot.toNIO,
+          ctx0
+        )
+      }
+    }
   }
 
   override def close(): Unit = {
@@ -37,6 +74,18 @@ class ScoverageReportWorker extends AutoCloseable {
 }
 
 object ScoverageReportWorker extends ExternalModule {
+  import ScoverageReportWorkerApi2.ReportType
+
+  trait ScoverageReportWorkerApiBridge {
+    def report(
+        reportType: ReportType,
+        sources: Seq[os.Path],
+        dataDirs: Seq[os.Path],
+        sourceRoot: os.Path
+    )(implicit
+        ctx: Ctx
+    ): Unit
+  }
 
   def scoverageReportWorker: Worker[ScoverageReportWorker] =
     Task.Worker { new ScoverageReportWorker() }
diff --git a/contrib/scoverage/worker2/src/mill/contrib/scoverage/worker/ScoverageReportWorkerImpl.scala b/contrib/scoverage/worker2/src/mill/contrib/scoverage/worker/ScoverageReportWorkerImpl.scala
index a478a91c533a..1393af627f1a 100644
--- a/contrib/scoverage/worker2/src/mill/contrib/scoverage/worker/ScoverageReportWorkerImpl.scala
+++ b/contrib/scoverage/worker2/src/mill/contrib/scoverage/worker/ScoverageReportWorkerImpl.scala
@@ -1,42 +1,46 @@
 package mill.contrib.scoverage.worker
 
-import mill.contrib.scoverage.api.ScoverageReportWorkerApi
 import _root_.scoverage.reporter.{
   CoberturaXmlWriter,
   CoverageAggregator,
   ScoverageHtmlWriter,
   ScoverageXmlWriter
 }
-import mill.api.Ctx
-import mill.contrib.scoverage.api.ScoverageReportWorkerApi.ReportType
+
+import mill.contrib.scoverage.api.ScoverageReportWorkerApi2
+import ScoverageReportWorkerApi2.ReportType
+import ScoverageReportWorkerApi2.Ctx
+
+import java.nio.file.Path
 
 /**
  * Scoverage Worker for Scoverage 2.x
  */
-class ScoverageReportWorkerImpl extends ScoverageReportWorkerApi {
+class ScoverageReportWorkerImpl extends ScoverageReportWorkerApi2 {
 
   override def report(
       reportType: ReportType,
-      sources: Seq[os.Path],
-      dataDirs: Seq[os.Path],
-      sourceRoot: os.Path
-  )(implicit ctx: Ctx): Unit =
+      sources: Array[Path],
+      dataDirs: Array[Path],
+      sourceRoot: Path,
+      ctx: Ctx
+  ): Unit =
     try {
       ctx.log.info(s"Processing coverage data for ${dataDirs.size} data locations")
-      CoverageAggregator.aggregate(dataDirs.map(_.toIO), sourceRoot.toIO) match {
+      CoverageAggregator.aggregate(dataDirs.map(_.toFile).toIndexedSeq, sourceRoot.toFile) match {
         case Some(coverage) =>
-          val sourceFolders = sources.map(_.toIO)
+          val sourceFolders = sources.map(_.toFile).toIndexedSeq
           val folder = ctx.dest
-          os.makeDir.all(folder)
+          ScoverageReportWorkerApi2.makeAllDirs(folder)
           reportType match {
             case ReportType.Html =>
-              new ScoverageHtmlWriter(sourceFolders, folder.toIO, None)
+              new ScoverageHtmlWriter(sourceFolders, folder.toFile, None)
                 .write(coverage)
             case ReportType.Xml =>
-              new ScoverageXmlWriter(sourceFolders, folder.toIO, false, None)
+              new ScoverageXmlWriter(sourceFolders, folder.toFile, false, None)
                 .write(coverage)
             case ReportType.XmlCobertura =>
-              new CoberturaXmlWriter(sourceFolders, folder.toIO, None)
+              new CoberturaXmlWriter(sourceFolders, folder.toFile, None)
                 .write(coverage)
             case ReportType.Console =>
               ctx.log.info(s"Statement coverage.: ${coverage.statementCoverageFormatted}%")
diff --git a/contrib/twirllib/src/mill/twirllib/TwirlModule.scala b/contrib/twirllib/src/mill/twirllib/TwirlModule.scala
index c2d6fad03b86..0c3269e78c2d 100644
--- a/contrib/twirllib/src/mill/twirllib/TwirlModule.scala
+++ b/contrib/twirllib/src/mill/twirllib/TwirlModule.scala
@@ -33,7 +33,7 @@ trait TwirlModule extends mill.Module { twirlModule =>
    * Replicate the logic from twirl build,
    *      see: https://github.com/playframework/twirl/blob/2.0.1/build.sbt#L12-L17
    */
-  private def scalaParserCombinatorsVersion: T[String] = twirlScalaVersion.map {
+  private def scalaParserCombinatorsVersion: Task[String] = twirlScalaVersion.map {
     case v if v.startsWith("2.") => "1.1.2"
     case _ => "2.3.0"
   }
@@ -57,7 +57,7 @@ trait TwirlModule extends mill.Module { twirlModule =>
    * @since Mill after 0.10.5
    */
   trait TwirlResolver extends CoursierModule {
-    override def resolveCoursierDependency: Task[Dep => Dependency] = Task.Anon { d: Dep =>
+    override def resolveCoursierDependency: Task[Dep => Dependency] = Task.Anon { (d: Dep) =>
       Lib.depToDependency(d, twirlScalaVersion())
     }
 
diff --git a/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala b/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
index a8094cc725b8..d881936fab24 100644
--- a/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
+++ b/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
@@ -7,6 +7,7 @@ import utest.{TestSuite, Tests, assert, _}
 
 trait HelloWorldTests extends TestSuite {
   val testTwirlVersion: String
+  val wildcard: String
 
   trait HelloWorldModule extends mill.twirllib.TwirlModule {
     def twirlVersion = testTwirlVersion
@@ -39,8 +40,8 @@ trait HelloWorldTests extends TestSuite {
   )
 
   def expectedDefaultImports: Seq[String] = Seq(
-    "import _root_.play.twirl.api.TwirlFeatureImports._",
-    "import _root_.play.twirl.api.TwirlHelperImports._",
+    s"import _root_.play.twirl.api.TwirlFeatureImports.$wildcard",
+    s"import _root_.play.twirl.api.TwirlHelperImports.$wildcard",
     "import _root_.play.twirl.api.Html",
     "import _root_.play.twirl.api.JavaScript",
     "import _root_.play.twirl.api.Txt",
@@ -48,8 +49,8 @@ trait HelloWorldTests extends TestSuite {
   )
 
   def testAdditionalImports: Seq[String] = Seq(
-    "mill.twirl.test.AdditionalImport1._",
-    "mill.twirl.test.AdditionalImport2._"
+    s"mill.twirl.test.AdditionalImport1.$wildcard",
+    s"mill.twirl.test.AdditionalImport2.$wildcard"
   )
 
   def testConstructorAnnotations = Seq(
@@ -159,13 +160,17 @@ trait HelloWorldTests extends TestSuite {
 
 object HelloWorldTests1_3 extends HelloWorldTests {
   override val testTwirlVersion = "1.3.16"
+  override val wildcard = "_"
 }
 object HelloWorldTests1_5 extends HelloWorldTests {
   override val testTwirlVersion = "1.5.2"
+  override val wildcard = "_"
 }
 object HelloWorldTests1_6 extends HelloWorldTests {
   override val testTwirlVersion = "1.6.2"
+  override val wildcard = "*"
 }
 object HelloWorldTests2_0 extends HelloWorldTests {
   override val testTwirlVersion = "2.0.1"
+  override val wildcard = "*"
 }
diff --git a/example/thirdparty/mockito/build.mill b/example/thirdparty/mockito/build.mill
index 0af38beb6ad1..9eab3b2ab0be 100644
--- a/example/thirdparty/mockito/build.mill
+++ b/example/thirdparty/mockito/build.mill
@@ -42,11 +42,20 @@ trait MockitoModule extends MavenModule{
   def testRuntimeIvyDeps: T[Agg[Dep]] = Agg.empty[Dep]
   def testFramework = "com.novocode.junit.JUnitFramework"
   def testForkArgs: T[Seq[String]] = Seq.empty[String]
+
+  def testFilteredSources: T[Seq[PathRef]] = Task { Seq.empty }
+
   object test extends MavenTests{
     def moduleDeps = super.moduleDeps ++ MockitoModule.this.testModuleDeps
     def testFramework = MockitoModule.this.testFramework
     def runIvyDeps = testRuntimeIvyDeps()
     def forkArgs = testForkArgs()
+    def allSourceFiles = Task {
+      val base = super.allSourceFiles()
+      val filtered = testFilteredSources().toSet
+      if (filtered.isEmpty) base
+      else base.filterNot(filtered.contains)
+    }
     def ivyDeps =
       testIvyDeps() ++
       Agg(
@@ -85,6 +94,11 @@ object `package` extends RootModule with MockitoModule{
     super.resources() ++ Seq(PathRef(Task.dest))
   }
 
+  def testFilteredSources: T[Seq[PathRef]] = Task {
+    // test `add_listeners_concurrently_sanity_check` is flaky
+    Seq(PathRef(millSourcePath / "src/test/java/org/mockitousage/debugging/StubbingLookupListenerCallbackTest.java"))
+  }
+
   object subprojects extends Module {
     object android extends MockitoModule {
       def moduleDeps = Seq(build)
diff --git a/example/thirdparty/netty/build.mill b/example/thirdparty/netty/build.mill
index f7b105790344..b9a1a7f30996 100644
--- a/example/thirdparty/netty/build.mill
+++ b/example/thirdparty/netty/build.mill
@@ -253,8 +253,8 @@ object common extends NettyModule{
     val shell = new groovy.lang.GroovyShell()
 
     val context = new java.util.HashMap[String, Object]
-    context.put("collection.template.dir", Task.workspace + "/common/src/main/templates")
-    context.put("collection.template.test.dir", Task.workspace + "/common/src/test/templates")
+    context.put("collection.template.dir", s"${Task.workspace}/common/src/main/templates")
+    context.put("collection.template.test.dir", s"${Task.workspace}/common/src/test/templates")
     context.put("collection.src.dir", (Task.dest / "src").toString)
     context.put("collection.testsrc.dir", (Task.dest / "testsrc").toString)
     shell.setProperty("properties", context)
diff --git a/integration/invalidation/multi-level-editing/resources/mill-build/mill-build/build.mill b/integration/invalidation/multi-level-editing/resources/mill-build/mill-build/build.mill
index 7d6f134d94e7..4efe9a06fcdf 100644
--- a/integration/invalidation/multi-level-editing/resources/mill-build/mill-build/build.mill
+++ b/integration/invalidation/multi-level-editing/resources/mill-build/mill-build/build.mill
@@ -8,7 +8,7 @@ object `package` extends MillBuildRootModule {
       Task.dest / "MetaConstant.scala",
       """package constant
         |object MetaConstant{
-        |  def scalatagsVersion = "0.8.2"
+        |  def scalatagsVersion = "0.13.1"
         |}
         |""".stripMargin
     )
diff --git a/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala b/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
index ba9554d6c7a7..c799d0f65876 100644
--- a/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
+++ b/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
@@ -87,7 +87,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       assert(res.isSuccess == false)
       // Prepend a "\n" to allow callsites to use "\n" to test for start of
       // line, even though the first line doesn't have a "\n" at the start
-      val err = "\n" + res.err
+      val err = "```\n" + res.err + "\n```"
       for (expected <- expectedSnippets) {
         assert(err.contains(expected))
       }
@@ -130,7 +130,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
 
     test("validEdits") - integrationTest { tester =>
       import tester._
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -143,7 +143,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       checkChangedClassloaders(tester, null, true, true, true)
 
       modifyFile(workspacePath / "foo/src/Example.scala", _.replace("!", "?"))
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>?")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>?")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -155,7 +155,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       checkChangedClassloaders(tester, null, false, false, false)
 
       modifyFile(workspacePath / "build.mill", _.replace("hello", "HELLO"))
-      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>0.8.2</p>?")
+      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>0.13.1</p>?")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -169,7 +169,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         workspacePath / "mill-build/build.mill",
         _.replace("def scalatagsVersion = ", "def scalatagsVersion = \"changed-\" + ")
       )
-      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>changed-0.8.2</p>?")
+      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>changed-0.13.1</p>?")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -181,7 +181,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
 
       modifyFile(
         workspacePath / "mill-build/mill-build/build.mill",
-        _.replace("0.8.2", "0.12.0")
+        _.replace("0.13.1", "0.12.0")
       )
       runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>changed-0.12.0</p>?")
       checkWatchedFiles(
@@ -195,9 +195,9 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
 
       modifyFile(
         workspacePath / "mill-build/mill-build/build.mill",
-        _.replace("0.12.0", "0.8.2")
+        _.replace("0.12.0", "0.13.1")
       )
-      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>changed-0.8.2</p>?")
+      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>changed-0.13.1</p>?")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -211,7 +211,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         workspacePath / "mill-build/build.mill",
         _.replace("def scalatagsVersion = \"changed-\" + ", "def scalatagsVersion = ")
       )
-      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>0.8.2</p>?")
+      runAssertSuccess(tester, "<h1>HELLO</h1><p>world</p><p>0.13.1</p>?")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -222,7 +222,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       checkChangedClassloaders(tester, null, true, true, false)
 
       modifyFile(workspacePath / "build.mill", _.replace("HELLO", "hello"))
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>?")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>?")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -233,7 +233,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       checkChangedClassloaders(tester, null, true, false, false)
 
       modifyFile(workspacePath / "foo/src/Example.scala", _.replace("?", "!"))
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -252,7 +252,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       def fixParseError(p: os.Path) =
         modifyFile(p, _.replace("extendx", "extends"))
 
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -300,7 +300,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       checkChangedClassloaders(tester, null, null, null, null)
 
       fixParseError(workspacePath / "build.mill")
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -319,7 +319,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       def fixCompileError(p: os.Path) =
         modifyFile(p, _.replace("import doesnt.exist", ""))
 
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -336,7 +336,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         // Ensure the file path in the compile error is properly adjusted to point
         // at the original source file and not the generated file
         (workspacePath / "build.mill").toString,
-        "not found: value doesnt"
+        "Not found: doesnt"
       )
       checkWatchedFiles(tester, Nil, buildPaths(tester), buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, false, false)
@@ -346,7 +346,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/build.mill").toString,
-        "not found: object doesnt"
+        "Not found: doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, false)
@@ -356,7 +356,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/mill-build/build.mill").toString,
-        "not found: object doesnt"
+        "Not found: doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, Nil, buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, null)
@@ -366,7 +366,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/build.mill").toString,
-        "not found: object doesnt"
+        "Not found: doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, true)
@@ -376,13 +376,13 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "build.mill").toString,
-        "not found: value doesnt"
+        "Not found: doesnt"
       )
       checkWatchedFiles(tester, Nil, buildPaths(tester), buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, true, false)
 
       fixCompileError(workspacePath / "build.mill")
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -407,7 +407,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       def fixRuntimeError(p: os.Path) =
         modifyFile(p, _.replaceFirst(Regex.quote(runErrorSnippet), "\\{"))
 
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),
@@ -475,7 +475,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
       checkChangedClassloaders(tester, null, true, true, false)
 
       fixRuntimeError(workspacePath / "build.mill")
-      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.8.2</p>!")
+      runAssertSuccess(tester, "<h1>hello</h1><p>world</p><p>0.13.1</p>!")
       checkWatchedFiles(
         tester,
         fooPaths(tester),

From 9cd9cf60487f2be328e90bbfb3c47b1bb5781076 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 02:46:57 +0200
Subject: [PATCH 02/13] wip

---
 build.mill                                    |  1 +
 main/api/src/mill/api/AggWrapper.scala        | 19 ++++----
 main/api/src/mill/api/ClassLoader.scala       |  2 +-
 main/api/src/mill/api/Ctx.scala               |  8 ++--
 main/api/src/mill/api/FixSizedCache.scala     |  2 +-
 main/api/src/mill/api/JarOps.scala            |  6 +--
 main/api/src/mill/api/JsonFormatters.scala    |  2 +-
 main/api/src/mill/api/KeyedLockedCache.scala  |  2 +-
 main/api/src/mill/api/PathRef.scala           |  6 ++-
 main/api/src/mill/api/Result.scala            | 18 ++++---
 main/api/src/mill/api/Retry.scala             |  4 +-
 main/api/src/mill/api/SystemStreams.scala     |  6 +--
 main/codesig/package.mill                     |  3 +-
 main/codesig/src/JvmModel.scala               |  2 +-
 main/codesig/src/ResolvedCalls.scala          |  4 +-
 main/codesig/src/SpanningForest.scala         |  6 ++-
 .../basic/17-scala-lambda/src/Hello.scala     |  7 ++-
 .../src/Hello.scala                           |  5 +-
 .../6-classes-misc-scala/src/Hello.scala      |  2 +-
 .../8-linked-list-scala/src/Hello.scala       |  4 +-
 .../realistic/5-parser/src/Hello.scala        | 32 +++++++++++--
 .../test/src/mill/define/BasePathTests.scala  | 20 ++++----
 main/eval/src/mill/eval/EvaluatorCore.scala   | 37 ++++++++-------
 main/eval/src/mill/eval/GroupEvaluator.scala  |  4 +-
 .../test/src/mill/eval/EvaluationTests.scala  | 47 ++++++++++---------
 main/init/src/mill/init/InitModule.scala      |  5 +-
 main/package.mill                             | 18 ++++++-
 .../src/mill/resolve/ExpandBraces.scala       |  4 +-
 main/resolve/src/mill/resolve/ParseArgs.scala |  2 +-
 .../mill/resolve/ResolveNotFoundHandler.scala |  6 +--
 main/server/src/mill/main/server/Server.scala |  3 +-
 main/src/mill/main/MainModule.scala           |  4 +-
 main/util/src/mill/util/PrefixLogger.scala    |  6 +--
 33 files changed, 182 insertions(+), 115 deletions(-)

diff --git a/build.mill b/build.mill
index f4a9b0f2e24d..151635a59a4e 100644
--- a/build.mill
+++ b/build.mill
@@ -56,6 +56,7 @@ object Deps {
   // When updating, run "Publish Bridges" Github Actions for the new version
   // and then add to it `bridgeScalaVersions`
   val scalaVersion = "2.13.14"
+  val scala2Version = "2.13.14"
   // The Scala 2.12.x version to use for some workers
   val workerScalaVersion212 = "2.12.19"
 
diff --git a/main/api/src/mill/api/AggWrapper.scala b/main/api/src/mill/api/AggWrapper.scala
index 063828464378..31f27082915b 100644
--- a/main/api/src/mill/api/AggWrapper.scala
+++ b/main/api/src/mill/api/AggWrapper.scala
@@ -33,11 +33,11 @@ private[mill] sealed class AggWrapper(strictUniqueness: Boolean) {
     def map[T](f: V => T): Agg[T]
     def filter(f: V => Boolean): Agg[V]
 
-    def collect[T](f: PartialFunction[V, T]): Agg[T]
-    def zipWithIndex: Agg[(V, Int)]
+    override def collect[T](f: PartialFunction[V, T]): Agg[T] = super.collect(f)
+    override def zipWithIndex: Agg[(V, Int)] = super.zipWithIndex
     def reverse: Agg[V]
     def zip[T](other: Agg[T]): Agg[(V, T)]
-    def ++[T >: V](other: IterableOnce[T]): Agg[T]
+    // def ++[T >: V](other: IterableOnce[T]): Agg[T] // error overriding final method ++ in trait IterableOps
     def length: Int
     def isEmpty: Boolean
     def foreach[U](f: V => U): Unit
@@ -85,16 +85,15 @@ private[mill] sealed class AggWrapper(strictUniqueness: Boolean) {
         Mutable.newBuilder[V]
       }
 
-      private[this] val set0 = mutable.LinkedHashSet.empty[V]
+      private val set0 = mutable.LinkedHashSet.empty[V]
 
       def contains(v: V): Boolean = set0.contains(v)
       def coll: Mutable[V] = this
 
-      override def toIterable: Iterable[V] = set0.toIterable
+      override def toIterable: Iterable[V] = set0
       def append(v: V): AnyVal = {
         if (!contains(v)) {
-          set0.add(v)
-
+          return set0.add(v)
         } else if (strictUniqueness) {
           throw new Exception("Duplicated item inserted into OrderedSet: " + v)
         }
@@ -118,7 +117,9 @@ private[mill] sealed class AggWrapper(strictUniqueness: Boolean) {
 
       override def filter(f: V => Boolean): Mutable[V] = {
         val output = new Agg.Mutable[V]
-        for (i <- items) if (f(i)) output.append(i)
+        for (i <- items) if (f(i)) {
+          val _ = output.append(i)
+        }
         output
       }
 
@@ -148,7 +149,7 @@ private[mill] sealed class AggWrapper(strictUniqueness: Boolean) {
       def iterator: Iterator[V] = items
       override def hashCode(): Int = items.map(_.hashCode()).sum
       override def equals(other: Any): Boolean = other match {
-        case s: Agg[_] => items.sameElements(s.items)
+        case s: Agg[?] => items.sameElements(s.items)
         case _ => super.equals(other)
       }
       override def toString: String = items.mkString("Agg(", ", ", ")")
diff --git a/main/api/src/mill/api/ClassLoader.scala b/main/api/src/mill/api/ClassLoader.scala
index 6f2b5ec7f2bb..5db97159d63a 100644
--- a/main/api/src/mill/api/ClassLoader.scala
+++ b/main/api/src/mill/api/ClassLoader.scala
@@ -26,7 +26,7 @@ object ClassLoader {
       makeUrls(urls).toArray,
       refinePlatformParent(parent)
     ) {
-      override def findClass(name: String): Class[_] = {
+      override def findClass(name: String): Class[?] = {
         if (sharedPrefixes.exists(name.startsWith)) {
           logger.foreach(
             _.debug(s"About to load class [${name}] from shared classloader [${sharedLoader}]")
diff --git a/main/api/src/mill/api/Ctx.scala b/main/api/src/mill/api/Ctx.scala
index ca08069896b0..59ad59d3d67e 100644
--- a/main/api/src/mill/api/Ctx.scala
+++ b/main/api/src/mill/api/Ctx.scala
@@ -73,7 +73,7 @@ object Ctx {
   }
 
   trait Args {
-    def args: IndexedSeq[_]
+    def args: IndexedSeq[?]
   }
 
   /**
@@ -167,7 +167,7 @@ object Ctx {
  * implementation of a `Task`.
  */
 class Ctx(
-    val args: IndexedSeq[_],
+    val args: IndexedSeq[?],
     dest0: () => os.Path,
     val log: Logger,
     val home: os.Path,
@@ -185,7 +185,7 @@ class Ctx(
     with Ctx.Workspace {
 
   def this(
-      args: IndexedSeq[_],
+      args: IndexedSeq[?],
       dest0: () => os.Path,
       log: Logger,
       home: os.Path,
@@ -194,7 +194,7 @@ class Ctx(
       testReporter: TestReporter,
       workspace: os.Path
   ) = {
-    this(args, dest0, log, home, env, reporter, testReporter, workspace, i => ???, null)
+    this(args, dest0, log, home, env, reporter, testReporter, workspace, _ => ???, null)
   }
   def dest: os.Path = dest0()
   def arg[T](index: Int): T = {
diff --git a/main/api/src/mill/api/FixSizedCache.scala b/main/api/src/mill/api/FixSizedCache.scala
index 5d71874246b6..0ba0f2a12e5d 100644
--- a/main/api/src/mill/api/FixSizedCache.scala
+++ b/main/api/src/mill/api/FixSizedCache.scala
@@ -15,7 +15,7 @@ import java.util.concurrent.{ConcurrentHashMap, Semaphore}
 class FixSizedCache[T](perKeySize: Int) extends KeyedLockedCache[T] {
 
   // Cache Key -> (Semaphore, Array of cached elements)
-  private[this] val keyToCache: ConcurrentHashMap[Long, (Semaphore, Array[(Boolean, Option[T])])] =
+  private val keyToCache: ConcurrentHashMap[Long, (Semaphore, Array[(Boolean, Option[T])])] =
     new ConcurrentHashMap
 
   override def withCachedValue[V](key: Long)(f: => T)(f2: T => V): V = {
diff --git a/main/api/src/mill/api/JarOps.scala b/main/api/src/mill/api/JarOps.scala
index 9f2e0d2a7376..540c706ca29d 100644
--- a/main/api/src/mill/api/JarOps.scala
+++ b/main/api/src/mill/api/JarOps.scala
@@ -73,7 +73,7 @@ trait JarOps {
     os.remove.all(jar)
 
     val seen = mutable.Set.empty[os.RelPath]
-    seen.add(os.sub / "META-INF/MANIFEST.MF")
+    val _ = seen.add(os.sub / "META-INF/MANIFEST.MF")
 
     val jarStream = new JarOutputStream(
       new BufferedOutputStream(new FileOutputStream(jar.toIO)),
@@ -84,7 +84,7 @@ trait JarOps {
       assert(inputPaths.iterator.forall(os.exists(_)))
 
       if (includeDirs) {
-        seen.add(os.sub / "META-INF")
+        val _ = seen.add(os.sub / "META-INF")
         val entry = new JarEntry("META-INF/")
         entry.setTime(curTime)
         jarStream.putNextEntry(entry)
@@ -99,7 +99,7 @@ trait JarOps {
           else os.walk(p).map(sub => (sub, sub.subRelativeTo(p))).sorted
         if (includeDirs || os.isFile(file)) && !seen(mapping) && fileFilter(p, mapping)
       } {
-        seen.add(mapping)
+        val _ = seen.add(mapping)
         val name = mapping.toString() + (if (os.isDir(file)) "/" else "")
         val entry = new JarEntry(name)
         entry.setTime(mTime(file))
diff --git a/main/api/src/mill/api/JsonFormatters.scala b/main/api/src/mill/api/JsonFormatters.scala
index dda6a1c3cc1b..bf1b448955fd 100644
--- a/main/api/src/mill/api/JsonFormatters.scala
+++ b/main/api/src/mill/api/JsonFormatters.scala
@@ -62,7 +62,7 @@ trait JsonFormatters {
         )
     )
 
-  implicit def enumFormat[T <: java.lang.Enum[_]: ClassTag]: RW[T] =
+  implicit def enumFormat[T <: java.lang.Enum[?]: ClassTag]: RW[T] =
     upickle.default.readwriter[String].bimap(
       _.name(),
       (s: String) =>
diff --git a/main/api/src/mill/api/KeyedLockedCache.scala b/main/api/src/mill/api/KeyedLockedCache.scala
index 7a8fc21a92fd..3ee62796f3cd 100644
--- a/main/api/src/mill/api/KeyedLockedCache.scala
+++ b/main/api/src/mill/api/KeyedLockedCache.scala
@@ -11,7 +11,7 @@ trait KeyedLockedCache[T] {
 
 object KeyedLockedCache {
   class RandomBoundedCache[T](hotParallelism: Int, coldCacheSize: Int) extends KeyedLockedCache[T] {
-    private[this] val random = new scala.util.Random(313373)
+    private val random = new scala.util.Random(313373)
     val available = new java.util.concurrent.Semaphore(hotParallelism)
 
     // Awful asymptotic complexity, but our caches are tiny n < 10 so it doesn't matter
diff --git a/main/api/src/mill/api/PathRef.scala b/main/api/src/mill/api/PathRef.scala
index ad1ae5a44eb0..483efa569c17 100644
--- a/main/api/src/mill/api/PathRef.scala
+++ b/main/api/src/mill/api/PathRef.scala
@@ -1,10 +1,13 @@
 package mill.api
 
+import scala.language.implicitConversions
+
 import java.nio.{file => jnio}
 import java.security.{DigestOutputStream, MessageDigest}
 import java.util.concurrent.ConcurrentHashMap
 import scala.util.{DynamicVariable, Using}
 import upickle.default.{ReadWriter => RW}
+import scala.annotation.nowarn
 
 /**
  * A wrapper around `os.Path` that calculates it's hashcode based
@@ -69,7 +72,7 @@ object PathRef {
           if (pathRef.sig != changedSig) {
             throw new PathRefValidationException(pathRef)
           }
-          map.put(mapKey(pathRef), pathRef)
+          val _ = map.put(mapKey(pathRef), pathRef)
       }
     }
     def clear(): Unit = map.clear()
@@ -197,6 +200,7 @@ object PathRef {
   )
 
   // scalafix:off; we want to hide the unapply method
+  @nowarn("msg=unused")
   private def unapply(pathRef: PathRef): Option[(os.Path, Boolean, Int, Revalidate)] = {
     Some((pathRef.path, pathRef.quick, pathRef.sig, pathRef.revalidate))
   }
diff --git a/main/api/src/mill/api/Result.scala b/main/api/src/mill/api/Result.scala
index ad7af1e051bf..afe73a5c2d1e 100644
--- a/main/api/src/mill/api/Result.scala
+++ b/main/api/src/mill/api/Result.scala
@@ -13,9 +13,10 @@ sealed trait Result[+T] {
   def flatMap[V](f: T => Result[V]): Result[V]
   def asSuccess: Option[Result.Success[T]] = None
   def asFailing: Option[Result.Failing[T]] = None
-  def getOrThrow: T = this match {
+  def getOrThrow: T = (this: @unchecked) match {
     case Result.Success(v) => v
-    case f: Result.Failing[_] => throw f
+    case f: Result.Failing[?] => throw f
+    // no cases for Skipped or Aborted?
   }
 }
 
@@ -95,10 +96,15 @@ object Result {
         current = current.head.getCause :: current
       }
       current.reverse
-        .flatMap(ex =>
-          Seq(ex.toString) ++
-            ex.getStackTrace.dropRight(outerStack.value.length).map("    " + _)
-        )
+        .flatMap { ex =>
+          val elements = ex.getStackTrace.dropRight(outerStack.value.length)
+          val formatted =
+            // for some reason .map without the explicit ArrayOps conversion doesn't work,
+            // and results in `Result[String]` instead of `Array[String]`
+            new scala.collection.ArrayOps(elements).map("    " + _)
+          Seq(ex.toString) ++ formatted
+
+        }
         .mkString("\n")
     }
   }
diff --git a/main/api/src/mill/api/Retry.scala b/main/api/src/mill/api/Retry.scala
index 2398d4e87e79..ca35b0537f73 100644
--- a/main/api/src/mill/api/Retry.scala
+++ b/main/api/src/mill/api/Retry.scala
@@ -38,9 +38,9 @@ case class Retry(
         if (timeoutMillis == -1) t(retryCount)
         else {
           val result = Promise[T]
-          val thread = new Thread(() => {
+          val thread = new Thread({ () =>
             result.complete(scala.util.Try(t(retryCount)))
-          })
+          }: Runnable)
           thread.start()
           Await.result(result.future, Duration.apply(timeoutMillis, TimeUnit.MILLISECONDS))
         }
diff --git a/main/api/src/mill/api/SystemStreams.scala b/main/api/src/mill/api/SystemStreams.scala
index e42b34d80ed9..3912eb57042d 100644
--- a/main/api/src/mill/api/SystemStreams.scala
+++ b/main/api/src/mill/api/SystemStreams.scala
@@ -132,9 +132,9 @@ object SystemStreams {
   def setTopLevelSystemStreamProxy(): Unit = {
     // Make sure to initialize `Console` to cache references to the original
     // `System.{in,out,err}` streams before we redirect them
-    Console.out
-    Console.err
-    Console.in
+    val _ = Console.out
+    val _ = Console.err
+    val _ = Console.in
     System.setIn(ThreadLocalStreams.In)
     System.setOut(ThreadLocalStreams.Out)
     System.setErr(ThreadLocalStreams.Err)
diff --git a/main/codesig/package.mill b/main/codesig/package.mill
index 51c622e50544..7e0120def83e 100644
--- a/main/codesig/package.mill
+++ b/main/codesig/package.mill
@@ -47,7 +47,8 @@ object `package` extends RootModule with build.MillPublishScalaModule {
           build.Deps.mainargs,
           build.Deps.requests,
           build.Deps.osLib,
-          build.Deps.upickle
+          build.Deps.upickle,
+          build.Deps.sourcecode
         )
       }
     }
diff --git a/main/codesig/src/JvmModel.scala b/main/codesig/src/JvmModel.scala
index 00c36c8fd316..e63eeffa937f 100644
--- a/main/codesig/src/JvmModel.scala
+++ b/main/codesig/src/JvmModel.scala
@@ -139,7 +139,7 @@ object JvmModel {
 
     sealed class Prim(val pretty: String) extends JType
 
-    object Prim extends {
+    object Prim {
       def read(s: String): Prim = all(s(0))
 
       val all: Map[Char, Prim] = Map(
diff --git a/main/codesig/src/ResolvedCalls.scala b/main/codesig/src/ResolvedCalls.scala
index 7b2fe32a26dd..6bb5b5698f7a 100644
--- a/main/codesig/src/ResolvedCalls.scala
+++ b/main/codesig/src/ResolvedCalls.scala
@@ -113,7 +113,9 @@ object ResolvedCalls {
       val externalSamDefiners = externalSummary
         .directMethods
         .map { case (k, v) => (k, v.collect { case (sig, true) => sig }) }
-        .collect { case (k, Seq(v)) => (k, v) }
+        .collect { case (k, Seq(v)) =>
+          (k, v)
+        } // Scala 3.5.0-RC6 - can not infer MethodSig here
 
       val allSamDefiners = localSamDefiners ++ externalSamDefiners
 
diff --git a/main/codesig/src/SpanningForest.scala b/main/codesig/src/SpanningForest.scala
index 115d60b35548..dd870bd48270 100644
--- a/main/codesig/src/SpanningForest.scala
+++ b/main/codesig/src/SpanningForest.scala
@@ -36,7 +36,11 @@ object SpanningForest {
       .groupMap(_._1)(_._2)
 
     ResolvedCalls.breadthFirst(rootChangedNodeIndices) { index =>
-      val nextIndices = downstreamGraphEdges.getOrElse(index, Array())
+      val nextIndices =
+        downstreamGraphEdges.getOrElse(
+          index,
+          Array[Int]()
+        ) // needed to add explicit type for Scala 3.5.0-RC6
       // We build up the spanningForest during a normal breadth first search,
       // using the `nodeMapping` to quickly find an vertice's tree node so we
       // can add children to it. We need to duplicate the `seen.contains` logic
diff --git a/main/codesig/test/cases/callgraph/basic/17-scala-lambda/src/Hello.scala b/main/codesig/test/cases/callgraph/basic/17-scala-lambda/src/Hello.scala
index 45fdc0c8195c..d9c7a6141ff0 100644
--- a/main/codesig/test/cases/callgraph/basic/17-scala-lambda/src/Hello.scala
+++ b/main/codesig/test/cases/callgraph/basic/17-scala-lambda/src/Hello.scala
@@ -1,9 +1,14 @@
 package hello
 
 object Hello {
+
+  trait MyFunction0[T] {
+    def apply(): T
+  }
+
   def main(): Int = {
 
-    val foo = () => used()
+    val foo: MyFunction0[Int] = () => used()
     foo()
   }
   def used(): Int = 2
diff --git a/main/codesig/test/cases/callgraph/complicated/13-iterator-inherit-external-filter-scala/src/Hello.scala b/main/codesig/test/cases/callgraph/complicated/13-iterator-inherit-external-filter-scala/src/Hello.scala
index 7096870a717b..6861bc5ecf27 100644
--- a/main/codesig/test/cases/callgraph/complicated/13-iterator-inherit-external-filter-scala/src/Hello.scala
+++ b/main/codesig/test/cases/callgraph/complicated/13-iterator-inherit-external-filter-scala/src/Hello.scala
@@ -26,10 +26,11 @@ object Hello {
     private[this] var hdDefined: Boolean = false
 
     def hasNext: Boolean = hdDefined || {
-      do {
+      while ({
         if (!parent.hasNext) return false
         hd = parent.next()
-      } while (!pred(hd))
+        !pred(hd)
+      }) {}
       hdDefined = true
       true
     }
diff --git a/main/codesig/test/cases/callgraph/complicated/6-classes-misc-scala/src/Hello.scala b/main/codesig/test/cases/callgraph/complicated/6-classes-misc-scala/src/Hello.scala
index 39896097bae4..a724d7d6d3bd 100644
--- a/main/codesig/test/cases/callgraph/complicated/6-classes-misc-scala/src/Hello.scala
+++ b/main/codesig/test/cases/callgraph/complicated/6-classes-misc-scala/src/Hello.scala
@@ -32,7 +32,7 @@ class DoubleDetMatrix(aa: Float, ab: Float, ba: Float, bb: Float)
 }
 
 class LinkedList {
-  def push(i: Int) {
+  def push(i: Int): Unit = {
     val n = new Inner(i, head)
     head = n
   }
diff --git a/main/codesig/test/cases/callgraph/complicated/8-linked-list-scala/src/Hello.scala b/main/codesig/test/cases/callgraph/complicated/8-linked-list-scala/src/Hello.scala
index 061c4c14aebc..5235986b9203 100644
--- a/main/codesig/test/cases/callgraph/complicated/8-linked-list-scala/src/Hello.scala
+++ b/main/codesig/test/cases/callgraph/complicated/8-linked-list-scala/src/Hello.scala
@@ -9,7 +9,7 @@ object Hello {
     def head: A
     def tail: TestList[A]
 
-    def foreach[U](f: A => U) {
+    def foreach[U](f: A => U): Unit = {
       var these = this
       while (!these.isEmpty) {
         f(these.head)
@@ -21,7 +21,7 @@ object Hello {
   object TestNil extends TestList[Nothing] {
     def isEmpty = true
     def head = throw new Exception()
-    def tail = throw new Exception()
+    override def tail: Nothing = throw new Exception()
   }
 
   class TestCons[B](val head: B, val tl: TestList[B]) extends TestList[B] {
diff --git a/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala b/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala
index 1fb9a5a8a10d..334525b900e0 100644
--- a/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala
+++ b/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala
@@ -6,15 +6,15 @@ class Word(s: String) extends Phrase
 class Pair(lhs: Phrase, rhs: Phrase) extends Phrase
 
 object Parser {
-  def prefix[_: P] = P("hello" | "goodbye").!.map(new Word(_))
+  def prefix[_X: P] = P("hello" | "goodbye").!.map(new Word(_))
 
-  def suffix[_: P] = P("world" | "seattle").!.map(new Word(_))
+  def suffix[_X: P] = P("world" | "seattle").!.map(new Word(_))
 
-  def ws[_: P] = P(" ".rep(1))
+  def ws[_X: P] = P(" ".rep(1))
 
-  def parened[_: P] = P("(" ~ parser ~ ")")
+  def parened[_X: P] = P("(" ~ parser ~ ")")
 
-  def parser[_: P]: P[Phrase] = P((parened | prefix) ~ ws ~ (parened | suffix)).map {
+  def parser[_X: P]: P[Phrase] = P((parened | prefix) ~ ws ~ (parened | suffix)).map {
     case (lhs, rhs) => new Pair(lhs, rhs)
   }
 }
@@ -24,6 +24,21 @@ object Parser {
     "hello.Parser$#parened(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Parser$#parser(fastparse.ParsingRun)fastparse.ParsingRun"
     ],
+    "hello.Parser$#parse0$proxy8$1(fastparse.ParsingRun)fastparse.ParsingRun": [
+        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
+    ],
+    "hello.Parser$#parse0$proxy9$1(fastparse.ParsingRun)fastparse.ParsingRun": [
+        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
+    ],
+    "hello.Parser$#parse0$proxy9$2(fastparse.ParsingRun)fastparse.ParsingRun": [
+        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
+    ],
+    "hello.Parser$#parse0$proxy9$3(fastparse.ParsingRun)fastparse.ParsingRun": [
+        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
+    ],
+    "hello.Parser$#parse0$proxy9$4(fastparse.ParsingRun)fastparse.ParsingRun": [
+        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
+    ],
     "hello.Parser$#parser(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Pair#<init>(hello.Phrase,hello.Phrase)void",
         "hello.Parser$#parened(fastparse.ParsingRun)fastparse.ParsingRun",
@@ -34,9 +49,16 @@ object Parser {
     "hello.Parser$#prefix(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Word#<init>(java.lang.String)void"
     ],
+    "hello.Parser$#rec$1(fastparse.ParsingRun,int,fastparse.Implicits$Repeater,java.lang.Object,fastparse.ParsingRun,int,int,boolean,boolean,fastparse.internal.Msgs,fastparse.internal.Msgs)fastparse.ParsingRun": [
+        "hello.Parser$#end$1(int,fastparse.ParsingRun,fastparse.Implicits$Repeater,java.lang.Object,int,int,int,boolean)fastparse.ParsingRun",
+        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
+    ],
     "hello.Parser$#suffix(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Word#<init>(java.lang.String)void"
     ],
+    "hello.Parser$#ws(fastparse.ParsingRun)fastparse.ParsingRun": [
+        "hello.Parser$#rec$1(fastparse.ParsingRun,int,fastparse.Implicits$Repeater,java.lang.Object,fastparse.ParsingRun,int,int,boolean,boolean,fastparse.internal.Msgs,fastparse.internal.Msgs)fastparse.ParsingRun"
+    ],
     "hello.Parser.parened(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Parser$#<init>()void",
         "hello.Parser$#parened(fastparse.ParsingRun)fastparse.ParsingRun"
diff --git a/main/define/test/src/mill/define/BasePathTests.scala b/main/define/test/src/mill/define/BasePathTests.scala
index dce543ca02ba..55901cb9778a 100644
--- a/main/define/test/src/mill/define/BasePathTests.scala
+++ b/main/define/test/src/mill/define/BasePathTests.scala
@@ -5,6 +5,17 @@ import mill.testkit.TestBaseModule
 import utest._
 
 object BasePathTests extends TestSuite {
+
+  object overriddenBasePath extends TestBaseModule {
+    override def millSourcePath = os.pwd / "overriddenBasePathRootValue"
+    object nested extends Module {
+      override def millSourcePath = super.millSourcePath / "overriddenBasePathNested"
+      object nested extends Module {
+        override def millSourcePath = super.millSourcePath / "overriddenBasePathDoubleNested"
+      }
+    }
+  }
+
   val testGraphs = new TestGraphs
   val tests = Tests {
     def checkMillSourcePath[T <: Module](m: T)(f: T => Module, segments: String*): Unit = {
@@ -54,15 +65,6 @@ object BasePathTests extends TestSuite {
       checkMillSourcePath(TestGraphs.nestedCrosses)(_.cross("210").cross2("js"), "cross", "cross2")
     }
     test("overridden") {
-      object overriddenBasePath extends TestBaseModule {
-        override def millSourcePath = os.pwd / "overriddenBasePathRootValue"
-        object nested extends Module {
-          override def millSourcePath = super.millSourcePath / "overriddenBasePathNested"
-          object nested extends Module {
-            override def millSourcePath = super.millSourcePath / "overriddenBasePathDoubleNested"
-          }
-        }
-      }
       assert(
         overriddenBasePath.millSourcePath == os.pwd / "overriddenBasePathRootValue",
         overriddenBasePath.nested.millSourcePath == os.pwd / "overriddenBasePathRootValue/nested/overriddenBasePathNested",
diff --git a/main/eval/src/mill/eval/EvaluatorCore.scala b/main/eval/src/mill/eval/EvaluatorCore.scala
index bfc257316862..fdb2cfbcea45 100644
--- a/main/eval/src/mill/eval/EvaluatorCore.scala
+++ b/main/eval/src/mill/eval/EvaluatorCore.scala
@@ -265,10 +265,10 @@ private[mill] trait EvaluatorCore extends GroupEvaluator {
         c.getInterfaces.iterator.flatMap(resolveTransitiveParents)
     }
 
-    val classToTransitiveClasses = sortedGroups
+    val classToTransitiveClasses: Map[Class[?], IndexedSeq[Class[?]]] = sortedGroups
       .values()
       .flatten
-      .collect { case namedTask: NamedTask[_] => namedTask.ctx.enclosingCls }
+      .collect { case namedTask: NamedTask[?] => namedTask.ctx.enclosingCls }
       .map(cls => cls -> resolveTransitiveParents(cls).toVector)
       .toMap
 
@@ -277,22 +277,23 @@ private[mill] trait EvaluatorCore extends GroupEvaluator {
       .flatMap(_._2)
       .toSet
 
-    val allTransitiveClassMethods = allTransitiveClasses
-      .map { cls =>
-        val cMangledName = cls.getName.replace('.', '$')
-        cls -> cls.getDeclaredMethods
-          .flatMap { m =>
-            Seq(
-              m.getName -> m,
-              // Handle scenarios where private method names get mangled when they are
-              // not really JVM-private due to being accessed by Scala nested objects
-              // or classes https://github.com/scala/bug/issues/9306
-              m.getName.stripPrefix(cMangledName + "$$") -> m,
-              m.getName.stripPrefix(cMangledName + "$") -> m
-            )
-          }.toMap
-      }
-      .toMap
+    val allTransitiveClassMethods: Map[Class[?], Map[String, java.lang.reflect.Method]] =
+      allTransitiveClasses
+        .map { cls =>
+          val cMangledName = cls.getName.replace('.', '$')
+          cls -> cls.getDeclaredMethods
+            .flatMap { m =>
+              Seq(
+                m.getName -> m,
+                // Handle scenarios where private method names get mangled when they are
+                // not really JVM-private due to being accessed by Scala nested objects
+                // or classes https://github.com/scala/bug/issues/9306
+                m.getName.stripPrefix(cMangledName + "$$") -> m,
+                m.getName.stripPrefix(cMangledName + "$") -> m
+              )
+            }.toMap
+        }
+        .toMap
 
     (classToTransitiveClasses, allTransitiveClassMethods)
   }
diff --git a/main/eval/src/mill/eval/GroupEvaluator.scala b/main/eval/src/mill/eval/GroupEvaluator.scala
index 676505ecf985..a5db8328364c 100644
--- a/main/eval/src/mill/eval/GroupEvaluator.scala
+++ b/main/eval/src/mill/eval/GroupEvaluator.scala
@@ -383,7 +383,7 @@ private[mill] trait GroupEvaluator {
       .task
       .writerOpt
       .map { w =>
-        upickle.default.writeJs(v.value)(w.asInstanceOf[upickle.default.Writer[Any]])
+        upickle.default.writeJs(v.value)(using w.asInstanceOf[upickle.default.Writer[Any]])
       }
       .orElse {
         labelled.task.asWorker.map { w =>
@@ -438,7 +438,7 @@ private[mill] trait GroupEvaluator {
         _ <- Option.when(cached.inputsHash == inputsHash)(())
         reader <- labelled.task.readWriterOpt
         parsed <-
-          try Some(upickle.default.read(cached.value)(reader))
+          try Some(upickle.default.read(cached.value)(using reader))
           catch {
             case e: PathRef.PathRefValidationException =>
               logger.debug(
diff --git a/main/eval/test/src/mill/eval/EvaluationTests.scala b/main/eval/test/src/mill/eval/EvaluationTests.scala
index ea0462c123f6..021d57906637 100644
--- a/main/eval/test/src/mill/eval/EvaluationTests.scala
+++ b/main/eval/test/src/mill/eval/EvaluationTests.scala
@@ -1,6 +1,6 @@
 package mill.eval
 
-import mill.util.TestUtil.{Test, test}
+import mill.util.TestUtil.Test
 import mill.define.{TargetImpl, Task}
 import mill.T
 import mill.util.{TestGraphs, TestUtil}
@@ -61,9 +61,10 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
     object graphs extends TestGraphs()
     import graphs._
     import TestGraphs._
-    utest.test("evaluateSingle") {
+    import utest._
+    test("evaluateSingle") {
 
-      utest.test("singleton") {
+      test("singleton") {
         import singleton._
         val check = new Checker(singleton)
         // First time the target is evaluated
@@ -73,7 +74,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         // After incrementing the counter, it forces re-evaluation
         check(single, expValue = 1, expEvaled = Agg(single))
       }
-      utest.test("backtickIdentifiers") {
+      test("backtickIdentifiers") {
         import graphs.bactickIdentifiers._
         val check = new Checker(bactickIdentifiers)
 
@@ -85,7 +86,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         `up-target`.counter += 1
         check(`a-down-target`, expValue = 2, expEvaled = Agg(`up-target`, `a-down-target`))
       }
-      utest.test("pair") {
+      test("pair") {
         import pair._
         val check = new Checker(pair)
         check(down, expValue = 0, expEvaled = Agg(up, down))
@@ -96,7 +97,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         up.counter += 1
         check(down, expValue = 2, expEvaled = Agg(up, down))
       }
-      utest.test("anonTriple") {
+      test("anonTriple") {
         import anonTriple._
         val check = new Checker(anonTriple)
         val middle = down.inputs(0)
@@ -112,7 +113,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
 
         check(down, expValue = 3, expEvaled = Agg(middle, down))
       }
-      utest.test("diamond") {
+      test("diamond") {
         import diamond._
         val check = new Checker(diamond)
         check(down, expValue = 0, expEvaled = Agg(up, left, right, down))
@@ -130,7 +131,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         right.counter += 1
         check(down, expValue = 5, expEvaled = Agg(right, down))
       }
-      utest.test("anonDiamond") {
+      test("anonDiamond") {
         import anonDiamond._
         val check = new Checker(anonDiamond)
         val left = down.inputs(0).asInstanceOf[TestUtil.Test]
@@ -151,7 +152,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         check(down, expValue = 5, expEvaled = Agg(left, right, down))
       }
 
-      utest.test("bigSingleTerminal") {
+      test("bigSingleTerminal") {
         import bigSingleTerminal._
         val check = new Checker(bigSingleTerminal)
 
@@ -170,8 +171,8 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
       }
     }
 
-    utest.test("evaluateMixed") {
-      utest.test("separateGroups") {
+    test("evaluateMixed") {
+      test("separateGroups") {
         // Make sure that `left` and `right` are able to recompute separately,
         // even though one depends on the other
 
@@ -189,7 +190,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         assert(filtered3 == Agg(change, right))
 
       }
-      utest.test("triangleTask") {
+      test("triangleTask") {
 
         import triangleTask._
         val checker = new Checker(triangleTask)
@@ -197,7 +198,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         checker(left, 1, Agg(), extraEvaled = -1)
 
       }
-      utest.test("multiTerminalGroup") {
+      test("multiTerminalGroup") {
         import multiTerminalGroup._
 
         val checker = new Checker(multiTerminalGroup)
@@ -205,7 +206,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         checker(left, 1, Agg(left), extraEvaled = -1)
       }
 
-      utest.test("multiTerminalBoundary") {
+      test("multiTerminalBoundary") {
 
         import multiTerminalBoundary._
 
@@ -214,7 +215,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         checker(task2, 4, Agg(), extraEvaled = -1, secondRunNoOp = false)
       }
 
-      utest.test("overrideSuperTask") {
+      test("overrideSuperTask") {
         // Make sure you can override targets, call their supers, and have the
         // overridden target be allocated a spot within the overridden/ folder of
         // the main publicly-available target
@@ -234,7 +235,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
           !overridden.contains("object")
         )
       }
-      utest.test("overrideSuperCommand") {
+      test("overrideSuperCommand") {
         // Make sure you can override commands, call their supers, and have the
         // overridden command be allocated a spot within the super/ folder of
         // the main publicly-available command
@@ -261,7 +262,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
           !overridden.contains("object1")
         )
       }
-      utest.test("nullTasks") {
+      test("nullTasks") {
         import nullTasks._
         val checker = new Checker(nullTasks)
         checker(nullTarget1, null, Agg(nullTarget1), extraEvaled = -1)
@@ -288,7 +289,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         checker(nc4, null, Agg(nc4), extraEvaled = -1, secondRunNoOp = false)
       }
 
-      utest.test("tasksAreUncached") {
+      test("tasksAreUncached") {
         // Make sure the tasks `left` and `middle` re-compute every time, while
         // the target `right` does not
         //
@@ -301,7 +302,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
           var leftCount = 0
           var rightCount = 0
           var middleCount = 0
-          def up = Task { test.anon() }
+          def up = Task { TestUtil.test.anon() }
           def left = Task.Anon { leftCount += 1; up() + 1 }
           def middle = Task.Anon { middleCount += 1; 100 }
           def right = Task { rightCount += 1; 10000 }
@@ -352,7 +353,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         assert(leftCount == 4, middleCount == 4, rightCount == 1)
       }
     }
-    utest.test("stackableOverrides") {
+    test("stackableOverrides") {
       // Make sure you can override commands, call their supers, and have the
       // overridden command be allocated a spot within the super/ folder of
       // the main publicly-available command
@@ -376,7 +377,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
       )
       assert(os.read(checker.evaluator.outPath / "m/f.json").contains(" 6,"))
     }
-    utest.test("stackableOverrides2") {
+    test("stackableOverrides2") {
       // When the supers have the same name, qualify them until they are distinct
       import StackableOverrides2._
 
@@ -398,7 +399,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
       )
       assert(os.read(checker.evaluator.outPath / "m/f.json").contains(" 6,"))
     }
-    utest.test("stackableOverrides3") {
+    test("stackableOverrides3") {
       // When the supers have the same name, qualify them until they are distinct
       import StackableOverrides3._
 
@@ -420,7 +421,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
       )
       assert(os.read(checker.evaluator.outPath / "m/f.json").contains(" 6,"))
     }
-    utest.test("privateTasksInMixedTraits") {
+    test("privateTasksInMixedTraits") {
       // Make sure we can have private cached targets in different trait with the same name,
       // and caching still works when these traits are mixed together
       import PrivateTasksInMixedTraits._
diff --git a/main/init/src/mill/init/InitModule.scala b/main/init/src/mill/init/InitModule.scala
index 76b054427675..87bfcd41a04e 100644
--- a/main/init/src/mill/init/InitModule.scala
+++ b/main/init/src/mill/init/InitModule.scala
@@ -57,7 +57,7 @@ trait InitModule extends Module {
             val extractedPath = T.dest / extractedDirName
             val conflicting = for {
               p <- os.walk(extractedPath)
-              val rel = p.relativeTo(extractedPath)
+              rel = p.relativeTo(extractedPath)
               if os.exists(T.workspace / rel)
             } yield rel
 
@@ -97,7 +97,8 @@ trait InitModule extends Module {
   private def usingExamples[T](fun: Seq[(ExampleId, ExampleUrl)] => T): Try[T] =
     Using(getClass.getClassLoader.getResourceAsStream("exampleList.txt")) { exampleList =>
       val reader = upickle.default.reader[Seq[(ExampleId, ExampleUrl)]]
-      val exampleNames: Seq[(ExampleId, ExampleUrl)] = upickle.default.read(exampleList)(reader)
+      val exampleNames: Seq[(ExampleId, ExampleUrl)] =
+        upickle.default.read(exampleList)(using reader)
       fun(exampleNames)
     }
 }
diff --git a/main/package.mill b/main/package.mill
index 1ef11936329f..083d84bce055 100644
--- a/main/package.mill
+++ b/main/package.mill
@@ -5,6 +5,7 @@ import mill.scalalib._
 import mill.contrib.buildinfo.BuildInfo
 import mill.T
 import mill.define.Cross
+import mill.scalalib.api.ZincWorkerUtil
 
 object `package` extends RootModule with build.MillStableScalaModule with BuildInfo {
 
@@ -19,12 +20,19 @@ object `package` extends RootModule with build.MillStableScalaModule with BuildI
     ivy"guru.nidi:graphviz-java-min-deps:0.18.1"
   )
 
-  def compileIvyDeps = Agg(build.Deps.scalaReflect(scalaVersion()))
+  def compileIvyDeps = T {
+    if (ZincWorkerUtil.isScala3(scalaVersion())) Agg.empty else Agg(build.Deps.scalaReflect(scalaVersion()))
+  }
 
   def buildInfoPackageName = "mill.main"
 
   def buildInfoMembers = Seq(
     BuildInfo.Value("scalaVersion", scalaVersion(), "Scala version used to compile mill core."),
+    BuildInfo.Value(
+      "workerScalaVersion213",
+      build.Deps.scala2Version,
+      "Scala 2.13 version used by some workers."
+    ),
     BuildInfo.Value(
       "workerScalaVersion212",
       build.Deps.workerScalaVersion212,
@@ -97,9 +105,15 @@ object `package` extends RootModule with build.MillStableScalaModule with BuildI
 
   object define extends build.MillStableScalaModule {
     def moduleDeps = Seq(api, util)
-    def compileIvyDeps = Agg(build.Deps.scalaReflect(scalaVersion()))
+    def compileIvyDeps = T {
+      if (ZincWorkerUtil.isScala3(scalaVersion())) Agg(build.Deps.scalaCompiler(scalaVersion()))
+      else Agg(build.Deps.scalaReflect(scalaVersion()))
+    }
     def ivyDeps = Agg(
       build.Deps.millModuledefs,
+      // TODO: somewhere sourcecode is included transitively,
+      // but we need the latest version to bring the macro improvements.
+      build.Deps.sourcecode,
       // Necessary so we can share the JNA classes throughout the build process
       build.Deps.jna,
       build.Deps.jnaPlatform,
diff --git a/main/resolve/src/mill/resolve/ExpandBraces.scala b/main/resolve/src/mill/resolve/ExpandBraces.scala
index fe68892a7498..fdef17c5a1f1 100644
--- a/main/resolve/src/mill/resolve/ExpandBraces.scala
+++ b/main/resolve/src/mill/resolve/ExpandBraces.scala
@@ -10,7 +10,7 @@ private object ExpandBraces {
     case class Expand(values: List[List[Fragment]]) extends Fragment
   }
 
-  def expandRec(frags: List[Fragment]): List[List[String]] = frags match {
+  private[ExpandBraces] def expandRec(frags: List[Fragment]): List[List[String]] = frags match {
     case Nil => List(List())
     case head :: tail =>
       val tailStrings = expandRec(tail)
@@ -30,7 +30,7 @@ private object ExpandBraces {
   }
 
   def expandBraces(selectorString: String): Either[String, Seq[String]] = {
-    parse(selectorString, parser(_)) match {
+    parse(selectorString, parser(using _)) match {
       case f: Parsed.Failure => Left(s"Parsing exception ${f.msg}")
       case Parsed.Success(fragmentLists, _) =>
         Right(expandRec(fragmentLists.toList).map(_.mkString))
diff --git a/main/resolve/src/mill/resolve/ParseArgs.scala b/main/resolve/src/mill/resolve/ParseArgs.scala
index 36d6a8545b3b..ae32b9089bf4 100644
--- a/main/resolve/src/mill/resolve/ParseArgs.scala
+++ b/main/resolve/src/mill/resolve/ParseArgs.scala
@@ -88,7 +88,7 @@ object ParseArgs {
 
   def extractSegments(selectorString: String)
       : Either[String, (Option[Segments], Option[Segments])] =
-    parse(selectorString, selector(_)) match {
+    parse(selectorString, selector(using _)) match {
       case f: Parsed.Failure => Left(s"Parsing exception ${f.msg}")
       case Parsed.Success(selector, _) => Right(selector)
     }
diff --git a/main/resolve/src/mill/resolve/ResolveNotFoundHandler.scala b/main/resolve/src/mill/resolve/ResolveNotFoundHandler.scala
index 792cb9202280..7b6551ed1fa9 100644
--- a/main/resolve/src/mill/resolve/ResolveNotFoundHandler.scala
+++ b/main/resolve/src/mill/resolve/ResolveNotFoundHandler.scala
@@ -42,7 +42,7 @@ private object ResolveNotFoundHandler {
     val search = revSelectorsSoFar.render
 
     val lastSearchOpt = for {
-      Segment.Label(s) <- Option(lastSegment)
+      case Segment.Label(s) <- Option(lastSegment)
       if s != "_" && s != "__"
       possibility <- findMostSimilar(s, allPossibleNames)
     } yield "__." + possibility
@@ -71,13 +71,13 @@ private object ResolveNotFoundHandler {
   }
 
   def errorMsgLabel(
-      given: String,
+      `given`: String,
       possibleMembers: Set[String],
       prefixSegments: Segments,
       fullSegments: Segments,
       allPossibleNames: Set[String]
   ): String = {
-    val suggestion = findMostSimilar(given, possibleMembers) match {
+    val suggestion = findMostSimilar(`given`, possibleMembers) match {
       case None => hintListLabel(prefixSegments, fullSegments.value.last, allPossibleNames)
       case Some(similar) =>
         " Did you mean " +
diff --git a/main/server/src/mill/main/server/Server.scala b/main/server/src/mill/main/server/Server.scala
index 0852c4afef3a..9b24dab9d0d4 100644
--- a/main/server/src/mill/main/server/Server.scala
+++ b/main/server/src/mill/main/server/Server.scala
@@ -56,7 +56,8 @@ abstract class Server[T](
                   serverLog("handling run")
                   try handleRun(sock, initialSystemProperties)
                   catch {
-                    case e: Throwable => serverLog(e + "\n" + e.getStackTrace.mkString("\n"))
+                    case e: Throwable =>
+                      serverLog(e.toString + "\n" + e.getStackTrace.mkString("\n"))
                   } finally sock.close();
                   true
               }
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index df6ddd5a2398..1771b96608b9 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -438,7 +438,7 @@ trait MainModule extends BaseModule0 {
           for {
             workerSegments <- evaluator.workerCache.keys.toList
             if allSegments.exists(workerSegments.startsWith)
-            (_, Val(closeable: AutoCloseable)) <-
+            case (_, Val(closeable: AutoCloseable)) <-
               evaluator.mutableWorkerCache.remove(workerSegments)
           } {
             closeable.close()
@@ -481,7 +481,7 @@ trait MainModule extends BaseModule0 {
    */
   def shutdown(): Command[Unit] = Task.Command(exclusive = true) {
     Target.log.info("Shutting down Mill server...")
-    Target.ctx.systemExit(0)
+    Target.ctx().systemExit(0)
     ()
   }
 
diff --git a/main/util/src/mill/util/PrefixLogger.scala b/main/util/src/mill/util/PrefixLogger.scala
index 68cd02e7321e..47e8484bd822 100644
--- a/main/util/src/mill/util/PrefixLogger.scala
+++ b/main/util/src/mill/util/PrefixLogger.scala
@@ -67,11 +67,11 @@ class PrefixLogger(
 
   override def info(s: String): Unit = {
     reportKey(logPrefixKey)
-    logger0.info(infoColor(linePrefix) + s)
+    logger0.info("" + infoColor(linePrefix) + s)
   }
   override def error(s: String): Unit = {
     reportKey(logPrefixKey)
-    logger0.error(infoColor(linePrefix) + s)
+    logger0.error("" + infoColor(linePrefix) + s)
   }
   override def ticker(s: String): Unit = setPromptDetail(logPrefixKey, s)
   override def setPromptDetail(key: Seq[String], s: String): Unit = logger0.setPromptDetail(key, s)
@@ -90,7 +90,7 @@ class PrefixLogger(
 
   override def debug(s: String): Unit = {
     if (debugEnabled) reportKey(logPrefixKey)
-    logger0.debug(infoColor(linePrefix) + s)
+    logger0.debug("" + infoColor(linePrefix) + s)
   }
   override def debugEnabled: Boolean = logger0.debugEnabled
 

From d87ad0c6bb3df013b821acf066d21c6f1c343599 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 03:08:24 +0200
Subject: [PATCH 03/13] .

---
 bsp/src/mill/bsp/BSP.scala                    |   2 +-
 idea/src/mill/idea/GenIdea.scala              |   1 +
 main/src/mill/main/TokenReaders.scala         |   1 +
 .../linenumbers/resources/scalac-plugin.xml   |   4 -
 .../linenumbers/LineNumberCorrector.scala     |  65 ---
 .../mill/linenumbers/LineNumberPlugin.scala   |  44 --
 .../src/mill/scalajslib/ScalaJSModule.scala   |   4 +-
 .../mill/scalajslib/CompileLinkTests.scala    |   9 +-
 .../mill/scalajslib/EsModuleRemapTests.scala  |  10 +-
 .../scalajslib/FullOptESModuleTests.scala     |   5 +-
 .../mill/scalajslib/MultiModuleTests.scala    |   5 +-
 .../mill/scalajslib/NodeJSConfigTests.scala   |   7 +-
 .../mill/scalajslib/OutputPatternsTests.scala |   5 +-
 .../scalajslib/ScalaTestsErrorTests.scala     |   5 +-
 .../scalajslib/SmallModulesForTests.scala     |   5 +-
 .../src/mill/scalajslib/SourceMapTests.scala  |   5 +-
 .../scalajslib/TopLevelExportsTests.scala     |   5 +-
 .../src/mill/scalalib/CrossSbtModule.scala    |   1 -
 scalalib/src/mill/scalalib/Dep.scala          |   8 +-
 scalalib/src/mill/scalalib/JavaModule.scala   |  18 +-
 .../src/mill/scalalib/PublishModule.scala     |   6 +-
 scalalib/src/mill/scalalib/ScalaModule.scala  |   5 +-
 .../src/mill/scalalib/ZincWorkerModule.scala  |   5 +-
 .../dependency/updates/UpdatesFinder.scala    |   2 +-
 .../dependency/versions/VersionParser.scala   |   2 +-
 .../mill/scalalib/giter8/Giter8Module.scala   |  21 +-
 .../mill/scalalib/publish/VersionScheme.scala |   3 +-
 .../mill/scalalib/worker/ZincWorkerImpl.scala | 411 ++++++++++++++++--
 .../mill/scalanativelib/CompileRunTests.scala |   2 +-
 .../mill/scalanativelib/ExclusionsTests.scala |   1 +
 .../mill/scalanativelib/FeaturesTests.scala   |   1 +
 .../scalanativelib/ScalaTestsErrorTests.scala |   5 +-
 .../src/mill/testkit/IntegrationTester.scala  |   2 +-
 testkit/src/mill/testkit/UnitTester.scala     |   2 +-
 34 files changed, 494 insertions(+), 183 deletions(-)
 delete mode 100644 runner/linenumbers/resources/scalac-plugin.xml
 delete mode 100644 runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala
 delete mode 100644 runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala

diff --git a/bsp/src/mill/bsp/BSP.scala b/bsp/src/mill/bsp/BSP.scala
index 4eea72bc9b33..285383bb8758 100644
--- a/bsp/src/mill/bsp/BSP.scala
+++ b/bsp/src/mill/bsp/BSP.scala
@@ -1,7 +1,7 @@
 package mill.bsp
 
 import mill.api.{Ctx, PathRef}
-import mill.{Agg, T, Task}
+import mill.{Agg, T, Task, given}
 import mill.define.{Command, Discover, ExternalModule}
 import mill.main.BuildInfo
 import mill.eval.Evaluator
diff --git a/idea/src/mill/idea/GenIdea.scala b/idea/src/mill/idea/GenIdea.scala
index 31b7fab6ebe2..66c3f76224db 100644
--- a/idea/src/mill/idea/GenIdea.scala
+++ b/idea/src/mill/idea/GenIdea.scala
@@ -1,5 +1,6 @@
 package mill.idea
 
+import mill.given
 import mill.Task
 import mill.api.Result
 import mill.define.{Command, Discover, ExternalModule}
diff --git a/main/src/mill/main/TokenReaders.scala b/main/src/mill/main/TokenReaders.scala
index 60c1b03e5d03..44374818aba2 100644
--- a/main/src/mill/main/TokenReaders.scala
+++ b/main/src/mill/main/TokenReaders.scala
@@ -69,4 +69,5 @@ trait TokenReaders0 {
     case t: TokensReader.Leftover[_, _] => new LeftoverTaskTokenReader[T](t)
   }
 
+  def given = () // dummy for scala 2/3 compat
 }
diff --git a/runner/linenumbers/resources/scalac-plugin.xml b/runner/linenumbers/resources/scalac-plugin.xml
deleted file mode 100644
index 7a27d92f3f79..000000000000
--- a/runner/linenumbers/resources/scalac-plugin.xml
+++ /dev/null
@@ -1,4 +0,0 @@
-<plugin>
-    <name>mill-linenumber-plugin</name>
-    <classname>mill.linenumbers.LineNumberPlugin</classname>
-</plugin>
\ No newline at end of file
diff --git a/runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala b/runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala
deleted file mode 100644
index 74fa588f9e3c..000000000000
--- a/runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala
+++ /dev/null
@@ -1,65 +0,0 @@
-package mill.linenumbers
-
-import scala.tools.nsc.Global
-
-object LineNumberCorrector {
-  def apply(
-      g: Global,
-      lines: Seq[String],
-      adjustedFile: String
-  )(unit: g.CompilationUnit): g.Tree = {
-
-    val userCodeStartMarker = "//MILL_USER_CODE_START_MARKER"
-
-    import scala.reflect.internal.util._
-
-    val markerLine = lines.indexWhere(_.startsWith(userCodeStartMarker))
-
-    val topWrapperLen = lines.take(markerLine + 1).map(_.length).sum
-
-    val trimmedSource = new BatchSourceFile(
-      new scala.reflect.io.PlainFile(adjustedFile),
-      g.currentSource.content.drop(topWrapperLen)
-    )
-
-    import scala.reflect.internal.util._
-    object Transformer extends g.Transformer {
-      override def transform(tree: g.Tree) = {
-        val transformedTree = super.transform(tree)
-        // The `start` and `end` values in transparent/range positions are left
-        // untouched, because of some aggressive validation in scalac that checks
-        // that trees are not overlapping, and shifting these values here
-        // violates the invariant (which breaks Ammonite, potentially because
-        // of multi-stage).
-        // Moreover, we rely only on the "point" value (for error reporting).
-        // The ticket https://github.com/scala/scala-dev/issues/390 tracks down
-        // relaxing the aggressive validation.
-        val newPos = tree.pos match {
-          case s: TransparentPosition if s.start > topWrapperLen =>
-            new TransparentPosition(
-              trimmedSource,
-              s.start - topWrapperLen,
-              s.point - topWrapperLen,
-              s.end - topWrapperLen
-            )
-          case s: RangePosition if s.start > topWrapperLen =>
-            new RangePosition(
-              trimmedSource,
-              s.start - topWrapperLen,
-              s.point - topWrapperLen,
-              s.end - topWrapperLen
-            )
-          case s: OffsetPosition if s.start > topWrapperLen =>
-            new OffsetPosition(trimmedSource, s.point - topWrapperLen)
-          case s => s
-
-        }
-        transformedTree.pos = newPos
-
-        transformedTree
-      }
-    }
-    Transformer.transform(unit.body)
-  }
-
-}
diff --git a/runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala b/runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala
deleted file mode 100644
index b8f0aeee877a..000000000000
--- a/runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala
+++ /dev/null
@@ -1,44 +0,0 @@
-package mill.linenumbers
-
-import mill.main.client.CodeGenConstants.buildFileExtensions
-import scala.tools.nsc._
-import scala.tools.nsc.plugins.{Plugin, PluginComponent}
-
-/**
- * Used to capture the names in scope after every execution, reporting them
- * to the `output` function. Needs to be a compiler plugin so we can hook in
- * immediately after the `typer`
- */
-class LineNumberPlugin(val global: Global) extends Plugin {
-  override def init(options: List[String], error: String => Unit): Boolean = true
-  val name: String = "mill-linenumber-plugin"
-  val description = "Adjusts line numbers in the user-provided script to compensate for wrapping"
-  val components: List[PluginComponent] = List(
-    new PluginComponent {
-      val global = LineNumberPlugin.this.global
-      val runsAfter = List("parser")
-      val phaseName = "FixLineNumbers"
-      def newPhase(prev: Phase): Phase = new global.GlobalPhase(prev) {
-        def name = phaseName
-        def apply(unit: global.CompilationUnit): Unit = {
-          LineNumberPlugin.apply(global)(unit)
-        }
-      }
-    }
-  )
-}
-
-object LineNumberPlugin {
-  def apply(g: Global)(unit: g.CompilationUnit): Unit = {
-    if (buildFileExtensions.exists(ex => g.currentSource.file.name.endsWith(s".$ex"))) {
-
-      val str = new String(g.currentSource.content)
-      val lines = str.linesWithSeparators.toVector
-      val adjustedFile = lines
-        .collectFirst { case s"//MILL_ORIGINAL_FILE_PATH=$rest" => rest.trim }
-        .getOrElse(sys.error(g.currentSource.path))
-
-      unit.body = LineNumberCorrector(g, lines, adjustedFile)(unit)
-    }
-  }
-}
diff --git a/scalajslib/src/mill/scalajslib/ScalaJSModule.scala b/scalajslib/src/mill/scalajslib/ScalaJSModule.scala
index 1d88914ded0b..10b412d17415 100644
--- a/scalajslib/src/mill/scalajslib/ScalaJSModule.scala
+++ b/scalajslib/src/mill/scalajslib/ScalaJSModule.scala
@@ -76,7 +76,7 @@ trait ScalaJSModule extends scalalib.ScalaModule { outer =>
 
   def scalaJSLinkerClasspath: T[Loose.Agg[PathRef]] = Task {
     val commonDeps = Seq(
-      ivy"org.scala-js::scalajs-sbt-test-adapter:${scalaJSVersion()}"
+      ivy"org.scala-js:scalajs-sbt-test-adapter_2.13:${scalaJSVersion()}"
     )
     val scalajsImportMapDeps = scalaJSVersion() match {
       case s"1.$n.$_" if n.toIntOption.exists(_ >= 16) && scalaJSImportMap().nonEmpty =>
@@ -92,7 +92,7 @@ trait ScalaJSModule extends scalalib.ScalaModule { outer =>
         )
       case "1" =>
         Seq(
-          ivy"org.scala-js::scalajs-linker:${scalaJSVersion()}"
+          ivy"org.scala-js:scalajs-linker_2.13:${scalaJSVersion()}"
         ) ++ scalaJSJsEnvIvyDeps()
     }
     // we need to use the scala-library of the currently running mill
diff --git a/scalajslib/test/src/mill/scalajslib/CompileLinkTests.scala b/scalajslib/test/src/mill/scalajslib/CompileLinkTests.scala
index efd9e0ac40bb..43822fbe8702 100644
--- a/scalajslib/test/src/mill/scalajslib/CompileLinkTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/CompileLinkTests.scala
@@ -44,7 +44,7 @@ object CompileLinkTests extends TestSuite {
       )
 
       object `test-utest` extends ScalaJSTests with TestModule.Utest {
-        override def sources = Task.Sources { millSourcePath / "src/utest" }
+        override def sources = Task.Sources { this.millSourcePath / "src/utest" }
         val utestVersion = if (ZincWorkerUtil.isScala3(crossScalaVersion)) "0.7.7" else "0.7.5"
         override def ivyDeps = Agg(
           ivy"com.lihaoyi::utest::$utestVersion"
@@ -52,7 +52,7 @@ object CompileLinkTests extends TestSuite {
       }
 
       object `test-scalatest` extends ScalaJSTests with TestModule.ScalaTest {
-        override def sources = Task.Sources { millSourcePath / "src/scalatest" }
+        override def sources = Task.Sources { this.millSourcePath / "src/scalatest" }
         override def ivyDeps = Agg(
           ivy"org.scalatest::scalatest::3.1.2"
         )
@@ -68,7 +68,10 @@ object CompileLinkTests extends TestSuite {
       object test extends ScalaJSTests with TestModule.Utest
     }
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "hello-js-world"
diff --git a/scalajslib/test/src/mill/scalajslib/EsModuleRemapTests.scala b/scalajslib/test/src/mill/scalajslib/EsModuleRemapTests.scala
index 025fe0106791..488c051082ee 100644
--- a/scalajslib/test/src/mill/scalajslib/EsModuleRemapTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/EsModuleRemapTests.scala
@@ -25,7 +25,10 @@ object EsModuleRemapTests extends TestSuite {
       ESModuleImportMapping.Prefix("@stdlib/linspace", remapTo)
     )
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   object OldJsModule extends TestBaseModule with ScalaJSModule {
@@ -38,7 +41,10 @@ object EsModuleRemapTests extends TestSuite {
       ESModuleImportMapping.Prefix("@stdlib/linspace", remapTo)
     )
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "esModuleRemap"
diff --git a/scalajslib/test/src/mill/scalajslib/FullOptESModuleTests.scala b/scalajslib/test/src/mill/scalajslib/FullOptESModuleTests.scala
index 9da8030876fe..417b8a34c34a 100644
--- a/scalajslib/test/src/mill/scalajslib/FullOptESModuleTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/FullOptESModuleTests.scala
@@ -16,7 +16,10 @@ object FullOptESModuleTests extends TestSuite {
       override def moduleKind = ModuleKind.ESModule
     }
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "hello-js-world"
diff --git a/scalajslib/test/src/mill/scalajslib/MultiModuleTests.scala b/scalajslib/test/src/mill/scalajslib/MultiModuleTests.scala
index 7df52a447d1c..4ca8c7d6543f 100644
--- a/scalajslib/test/src/mill/scalajslib/MultiModuleTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/MultiModuleTests.scala
@@ -29,7 +29,10 @@ object MultiModuleTests extends TestSuite {
       override def millSourcePath = MultiModule.millSourcePath / "shared"
     }
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val evaluator = UnitTester(MultiModule, sourcePath)
diff --git a/scalajslib/test/src/mill/scalajslib/NodeJSConfigTests.scala b/scalajslib/test/src/mill/scalajslib/NodeJSConfigTests.scala
index 730866725fa1..3c6b3dca10c1 100644
--- a/scalajslib/test/src/mill/scalajslib/NodeJSConfigTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/NodeJSConfigTests.scala
@@ -43,7 +43,7 @@ object NodeJSConfigTests extends TestSuite {
       override def jsEnvConfig = Task { JsEnvConfig.NodeJs(args = nodeArgs) }
 
       object `test-utest` extends ScalaJSTests with TestModule.Utest {
-        override def sources = Task.Sources { millSourcePath / "src/utest" }
+        override def sources = Task.Sources { this.millSourcePath / "src/utest" }
         override def ivyDeps = Agg(
           ivy"com.lihaoyi::utest::$utestVersion"
         )
@@ -51,7 +51,10 @@ object NodeJSConfigTests extends TestSuite {
       }
     }
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "hello-js-world"
diff --git a/scalajslib/test/src/mill/scalajslib/OutputPatternsTests.scala b/scalajslib/test/src/mill/scalajslib/OutputPatternsTests.scala
index 34dbb7f9f6e0..4e4aaca417c9 100644
--- a/scalajslib/test/src/mill/scalajslib/OutputPatternsTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/OutputPatternsTests.scala
@@ -18,7 +18,10 @@ object OutputPatternsTests extends TestSuite {
       override def scalaJSOutputPatterns = OutputPatterns.fromJSFile("%s.mjs")
     }
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "hello-js-world"
diff --git a/scalajslib/test/src/mill/scalajslib/ScalaTestsErrorTests.scala b/scalajslib/test/src/mill/scalajslib/ScalaTestsErrorTests.scala
index 97d1d3e84e61..6b9f5165af47 100644
--- a/scalajslib/test/src/mill/scalajslib/ScalaTestsErrorTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/ScalaTestsErrorTests.scala
@@ -16,7 +16,10 @@ object ScalaTestsErrorTests extends TestSuite {
         override def hierarchyChecks(): Unit = {}
       }
     }
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   def tests: Tests = Tests {
diff --git a/scalajslib/test/src/mill/scalajslib/SmallModulesForTests.scala b/scalajslib/test/src/mill/scalajslib/SmallModulesForTests.scala
index 25c5c7150b25..07a155406f4a 100644
--- a/scalajslib/test/src/mill/scalajslib/SmallModulesForTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/SmallModulesForTests.scala
@@ -15,7 +15,10 @@ object SmallModulesForTests extends TestSuite {
     override def moduleKind = ModuleKind.ESModule
     override def moduleSplitStyle = ModuleSplitStyle.SmallModulesFor(List("app"))
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "small-modules-for"
diff --git a/scalajslib/test/src/mill/scalajslib/SourceMapTests.scala b/scalajslib/test/src/mill/scalajslib/SourceMapTests.scala
index a52ba7edaa3f..b83b11552ba8 100644
--- a/scalajslib/test/src/mill/scalajslib/SourceMapTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/SourceMapTests.scala
@@ -15,7 +15,10 @@ object SourceMapTests extends TestSuite {
       override def scalaJSSourceMap = false
     }
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "hello-js-world"
diff --git a/scalajslib/test/src/mill/scalajslib/TopLevelExportsTests.scala b/scalajslib/test/src/mill/scalajslib/TopLevelExportsTests.scala
index 6ea7bbaf780e..c3eba073ce87 100644
--- a/scalajslib/test/src/mill/scalajslib/TopLevelExportsTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/TopLevelExportsTests.scala
@@ -13,7 +13,10 @@ object TopLevelExportsTests extends TestSuite {
       sys.props.getOrElse("TEST_SCALAJS_VERSION", ???) // at least "1.8.0"
     override def moduleKind = ModuleKind.ESModule
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   val millSourcePath = os.Path(sys.env("MILL_TEST_RESOURCE_DIR")) / "top-level-exports"
diff --git a/scalalib/src/mill/scalalib/CrossSbtModule.scala b/scalalib/src/mill/scalalib/CrossSbtModule.scala
index 82434dc9d509..e80fce57571e 100644
--- a/scalalib/src/mill/scalalib/CrossSbtModule.scala
+++ b/scalalib/src/mill/scalalib/CrossSbtModule.scala
@@ -2,7 +2,6 @@ package mill.scalalib
 
 import mill.api.PathRef
 import mill.{T, Task}
-import mill.scalalib.{CrossModuleBase, SbtModule}
 
 import scala.annotation.nowarn
 
diff --git a/scalalib/src/mill/scalalib/Dep.scala b/scalalib/src/mill/scalalib/Dep.scala
index b857131bc50f..0c1d41bf3515 100644
--- a/scalalib/src/mill/scalalib/Dep.scala
+++ b/scalalib/src/mill/scalalib/Dep.scala
@@ -172,11 +172,11 @@ object Dep {
     (dep: Dep) =>
       unparse(dep) match {
         case Some(s) => ujson.Str(s)
-        case None => upickle.default.writeJs[Dep](dep)(rw0)
+        case None => upickle.default.writeJs[Dep](dep)(using rw0)
       },
     {
       case s: ujson.Str => parse(s.value)
-      case v: ujson.Value => upickle.default.read[Dep](v)(rw0)
+      case v: ujson.Value => upickle.default.read[Dep](v)(using rw0)
     }
   )
 
@@ -279,7 +279,7 @@ object BoundDep {
     upickle.default.readwriter[ujson.Value].bimap[BoundDep](
       bdep => {
         Dep.unparse(Dep(bdep.dep, CrossVersion.Constant("", false), bdep.force)) match {
-          case None => upickle.default.writeJs(bdep)(jsonify0)
+          case None => upickle.default.writeJs(bdep)(using jsonify0)
           case Some(s) => ujson.Str(s)
         }
       },
@@ -287,7 +287,7 @@ object BoundDep {
         case ujson.Str(s) =>
           val dep = Dep.parse(s)
           BoundDep(dep.dep, dep.force)
-        case v => upickle.default.read[BoundDep](v)(jsonify0)
+        case v => upickle.default.read[BoundDep](v)(using jsonify0)
       }
     )
 }
diff --git a/scalalib/src/mill/scalalib/JavaModule.scala b/scalalib/src/mill/scalalib/JavaModule.scala
index 90d72e7b62bd..d2293189b8b1 100644
--- a/scalalib/src/mill/scalalib/JavaModule.scala
+++ b/scalalib/src/mill/scalalib/JavaModule.scala
@@ -1,11 +1,11 @@
 package mill
 package scalalib
 
-import coursier.Repository
 import coursier.core.Resolution
 import coursier.parse.JavaOrScalaModule
 import coursier.parse.ModuleParser
 import coursier.util.ModuleMatcher
+import coursier.{Repository, Type}
 import mainargs.{Flag, arg}
 import mill.Agg
 import mill.api.{Ctx, JarManifest, MillException, PathRef, Result, internal}
@@ -155,6 +155,12 @@ trait JavaModule
    */
   def runIvyDeps: T[Agg[Dep]] = Task { Agg.empty[Dep] }
 
+  /**
+   * Default artifact types to fetch and put in the classpath. Add extra types
+   * here if you'd like fancy artifact extensions to be fetched.
+   */
+  def artifactTypes: T[Set[Type]] = Task { coursier.core.Resolution.defaultTypes }
+
   /**
    * Options to pass to the java compiler
    */
@@ -252,8 +258,10 @@ trait JavaModule
       else compileModuleDepsChecked
     val deps = (normalDeps ++ compileDeps).distinct
     val asString =
-      s"${if (recursive) "Recursive module"
-        else "Module"} dependencies of ${millModuleSegments.render}:\n\t${deps
+      s"${
+          if (recursive) "Recursive module"
+          else "Module"
+        } dependencies of ${millModuleSegments.render}:\n\t${deps
           .map { dep =>
             dep.millModuleSegments.render ++
               (if (compileModuleDepsChecked.contains(dep) || !normalDeps.contains(dep)) " (compile)"
@@ -551,7 +559,9 @@ trait JavaModule
   }
 
   def resolvedRunIvyDeps: T[Agg[PathRef]] = Task {
-    defaultResolver().resolveDeps(runIvyDeps().map(bindDependency()) ++ transitiveIvyDeps())
+    defaultResolver().resolveDeps(
+      runIvyDeps().map(bindDependency()) ++ transitiveIvyDeps()
+    )
   }
 
   /**
diff --git a/scalalib/src/mill/scalalib/PublishModule.scala b/scalalib/src/mill/scalalib/PublishModule.scala
index cefe014d11f1..eb3a7a22f01c 100644
--- a/scalalib/src/mill/scalalib/PublishModule.scala
+++ b/scalalib/src/mill/scalalib/PublishModule.scala
@@ -62,10 +62,11 @@ trait PublishModule extends JavaModule { outer =>
   }
 
   def publishXmlDeps: Task[Agg[Dependency]] = Task.Anon {
-    val ivyPomDeps = (ivyDeps() ++ mandatoryIvyDeps()).map(resolvePublishDependency().apply(_))
+    val ivyPomDeps =
+      (ivyDeps() ++ mandatoryIvyDeps()).map(resolvePublishDependency.apply().apply(_))
 
     val compileIvyPomDeps = compileIvyDeps()
-      .map(resolvePublishDependency().apply(_))
+      .map(resolvePublishDependency.apply().apply(_))
       .filter(!ivyPomDeps.contains(_))
       .map(_.copy(scope = Scope.Provided))
 
@@ -314,6 +315,7 @@ object PublishModule extends ExternalModule with TaskModule {
       (payload.map { case (p, f) => (p.path, f) }, meta)
   }
   object PublishData {
+    import mill.scalalib.publish.artifactFormat
     implicit def jsonify: upickle.default.ReadWriter[PublishData] = upickle.default.macroRW
   }
 
diff --git a/scalalib/src/mill/scalalib/ScalaModule.scala b/scalalib/src/mill/scalalib/ScalaModule.scala
index b2b839e55841..c91ef4add7b7 100644
--- a/scalalib/src/mill/scalalib/ScalaModule.scala
+++ b/scalalib/src/mill/scalalib/ScalaModule.scala
@@ -11,7 +11,10 @@ import mainargs.Flag
 import mill.scalalib.bsp.{BspBuildTarget, BspModule, ScalaBuildTarget, ScalaPlatform}
 import mill.scalalib.dependency.versions.{ValidVersion, Version}
 
+// this import requires scala-reflect library to be on the classpath
+// it was duplicated to scala3-compiler, but is that too powerful to add as a dependency?
 import scala.reflect.internal.util.ScalaClassLoader
+
 import scala.util.Using
 
 /**
@@ -56,7 +59,7 @@ trait ScalaModule extends JavaModule with TestModule.ScalaModuleBase { outer =>
   def scalaVersion: T[String]
 
   override def mapDependencies: Task[coursier.Dependency => coursier.Dependency] = Task.Anon {
-    super.mapDependencies().andThen { d: coursier.Dependency =>
+    super.mapDependencies().andThen { (d: coursier.Dependency) =>
       val artifacts =
         if (ZincWorkerUtil.isDotty(scalaVersion()))
           Set("dotty-library", "dotty-compiler")
diff --git a/scalalib/src/mill/scalalib/ZincWorkerModule.scala b/scalalib/src/mill/scalalib/ZincWorkerModule.scala
index 6861fdcacf08..eb2ebb6f6b1b 100644
--- a/scalalib/src/mill/scalalib/ZincWorkerModule.scala
+++ b/scalalib/src/mill/scalalib/ZincWorkerModule.scala
@@ -2,7 +2,6 @@ package mill.scalalib
 
 import coursier.Repository
 import mainargs.Flag
-import mill.Agg
 import mill._
 import mill.api.{Ctx, FixSizedCache, KeyedLockedCache, PathRef, Result}
 import mill.define.{ExternalModule, Discover}
@@ -127,8 +126,8 @@ trait ZincWorkerModule extends mill.Module with OfflineSupportModule { self: Cou
     val bridgeJar = resolveDependencies(
       repositories,
       Seq(bridgeDep.bindDep("", "", "")),
-      useSources,
-      Some(overrideScalaLibrary(scalaVersion, scalaOrganization))
+      sources = useSources,
+      mapDependencies = Some(overrideScalaLibrary(scalaVersion, scalaOrganization))
     ).map(deps =>
       ZincWorkerUtil.grepJar(deps, bridgeName, bridgeVersion, useSources)
     )
diff --git a/scalalib/src/mill/scalalib/dependency/updates/UpdatesFinder.scala b/scalalib/src/mill/scalalib/dependency/updates/UpdatesFinder.scala
index 863019599d50..3ef00db20d06 100644
--- a/scalalib/src/mill/scalalib/dependency/updates/UpdatesFinder.scala
+++ b/scalalib/src/mill/scalalib/dependency/updates/UpdatesFinder.scala
@@ -74,5 +74,5 @@ private[dependency] object UpdatesFinder {
     case (_, _) => false
   }
 
-  private def isUpdate(current: Version) = current < _
+  private def isUpdate(current: Version) = current < (_: Version)
 }
diff --git a/scalalib/src/mill/scalalib/dependency/versions/VersionParser.scala b/scalalib/src/mill/scalalib/dependency/versions/VersionParser.scala
index d4cb56c816fa..ef3757467b8e 100644
--- a/scalalib/src/mill/scalalib/dependency/versions/VersionParser.scala
+++ b/scalalib/src/mill/scalalib/dependency/versions/VersionParser.scala
@@ -27,5 +27,5 @@ private[dependency] object VersionParser {
     }
 
   def parse(text: String): Parsed[(Seq[Long], Seq[String], Seq[String])] =
-    fastparse.parse(text, versionParser(_))
+    fastparse.parse(text, versionParser(using _))
 }
diff --git a/scalalib/src/mill/scalalib/giter8/Giter8Module.scala b/scalalib/src/mill/scalalib/giter8/Giter8Module.scala
index c254512d2c8e..e7ab57573e2a 100644
--- a/scalalib/src/mill/scalalib/giter8/Giter8Module.scala
+++ b/scalalib/src/mill/scalalib/giter8/Giter8Module.scala
@@ -16,11 +16,22 @@ trait Giter8Module extends CoursierModule {
 
   def init(args: String*): Command[Unit] = Task.Command {
     T.log.info("Creating a new project...")
-    val giter8Dependencies = defaultResolver().resolveDeps {
-      val scalaBinVersion = ZincWorkerUtil.scalaBinaryVersion(BuildInfo.scalaVersion)
-      Loose.Agg(ivy"org.foundweekends.giter8:giter8_${scalaBinVersion}:0.14.0"
-        .bindDep("", "", ""))
-    }
+
+    val giter8Dependencies =
+      try {
+        defaultResolver().resolveDeps {
+          val scalaBinVersion = {
+            val bv = ZincWorkerUtil.scalaBinaryVersion(BuildInfo.scalaVersion)
+            if (bv == "3") "2.13" else bv
+          }
+          Loose.Agg(ivy"org.foundweekends.giter8:giter8_${scalaBinVersion}:0.14.0"
+            .bindDep("", "", ""))
+        }
+      } catch {
+        case e: Exception =>
+          T.log.error("Failed to resolve giter8 dependencies\n" + e.getMessage)
+          throw e
+      }
 
     Jvm.runSubprocess(
       "giter8.Giter8",
diff --git a/scalalib/src/mill/scalalib/publish/VersionScheme.scala b/scalalib/src/mill/scalalib/publish/VersionScheme.scala
index 8a53196c37a0..6fcba7457b53 100644
--- a/scalalib/src/mill/scalalib/publish/VersionScheme.scala
+++ b/scalalib/src/mill/scalalib/publish/VersionScheme.scala
@@ -33,5 +33,6 @@ object VersionScheme {
   case object Strict extends VersionScheme("strict")
   implicit val rwStrict: ReadWriter[Strict.type] = macroRW
 
-  implicit val rwVersionScheme: ReadWriter[VersionScheme.type] = macroRW
+  // edit @bishabosha: why was it `.type`, I assume it is meant to infer a sum type?
+  implicit val rwVersionScheme: ReadWriter[VersionScheme /*.type*/ ] = macroRW
 }
diff --git a/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala b/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
index 5b7c373992a2..7b53632afd8d 100644
--- a/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
+++ b/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
@@ -42,6 +42,7 @@ import xsbti.compile.{
 import xsbti.{PathBasedFile, VirtualFile}
 
 import java.io.{File, PrintWriter}
+import java.nio.charset.StandardCharsets
 import java.util.Optional
 import scala.annotation.tailrec
 import scala.collection.mutable
@@ -144,7 +145,7 @@ class ZincWorkerImpl(
       compilerClasspath,
       scalacPluginClasspath,
       Seq()
-    ) { compilers: Compilers =>
+    ) { (compilers: Compilers) =>
       if (ZincWorkerUtil.isDotty(scalaVersion) || ZincWorkerUtil.isScala3Milestone(scalaVersion)) {
         // dotty 0.x and scala 3 milestones use the dotty-doc tool
         val dottydocClass =
@@ -388,7 +389,7 @@ class ZincWorkerImpl(
       compilerClasspath = compilerClasspath,
       scalacPluginClasspath = scalacPluginClasspath,
       javacOptions = javacOptions
-    ) { compilers: Compilers =>
+    ) { (compilers: Compilers) =>
       compileInternal(
         upstreamCompileOutput = upstreamCompileOutput,
         sources = sources,
@@ -495,6 +496,8 @@ class ZincWorkerImpl(
       auxiliaryClassFileExtensions: Seq[String],
       zincCache: os.SubPath = os.sub / "zinc"
   )(implicit ctx: ZincWorkerApi.Ctx): Result[CompilationResult] = {
+    import ZincWorkerImpl.{ForwardingReporter, TransformingReporter, PositionMapper}
+
     os.makeDir.all(ctx.dest)
 
     val classesDir =
@@ -525,30 +528,21 @@ class ZincWorkerImpl(
     val loggerId = Thread.currentThread().getId.toString
     val logger = SbtLoggerUtils.createLogger(loggerId, consoleAppender, zincLogLevel)
 
-    val newReporter = reporter match {
-      case None => new ManagedLoggedReporter(10, logger) with RecordingReporter
-      case Some(forwarder) =>
-        new ManagedLoggedReporter(10, logger) with RecordingReporter {
-
-          override def logError(problem: xsbti.Problem): Unit = {
-            forwarder.logError(new ZincProblem(problem))
-            super.logError(problem)
-          }
-
-          override def logWarning(problem: xsbti.Problem): Unit = {
-            forwarder.logWarning(new ZincProblem(problem))
-            super.logWarning(problem)
-          }
-
-          override def logInfo(problem: xsbti.Problem): Unit = {
-            forwarder.logInfo(new ZincProblem(problem))
-            super.logInfo(problem)
-          }
-
-          override def printSummary(): Unit = {
-            forwarder.printSummary()
-            super.printSummary()
-          }
+    def mkNewReporter(mapper: (xsbti.Position => xsbti.Position)) = reporter match {
+      case None =>
+        new ManagedLoggedReporter(10, logger) with RecordingReporter
+          with TransformingReporter {
+          def color: Boolean = ctx.log.colored
+          def optPositionMapper = mapper
+        }
+      case Some(forwarder0) =>
+        new ManagedLoggedReporter(10, logger)
+          with ForwardingReporter
+          with RecordingReporter
+          with TransformingReporter {
+          def forwarder = forwarder0
+          def color: Boolean = ctx.log.colored
+          def optPositionMapper = mapper
         }
     }
     val analysisMap0 = upstreamCompileOutput.map(c => c.classes.path -> c.analysisFile).toMap
@@ -581,6 +575,10 @@ class ZincWorkerImpl(
       auxiliaryClassFileExtensions.map(new AuxiliaryClassFileExtension(_)).toArray
     )
 
+    val newReporter = mkNewReporter(
+      PositionMapper.create(virtualSources)
+    )
+
     val inputs = ic.inputs(
       classpath = classpath,
       sources = virtualSources,
@@ -673,6 +671,367 @@ class ZincWorkerImpl(
 }
 
 object ZincWorkerImpl {
+
+  /**
+   * TODO: copied from mill.scalalib.Assembly
+   */
+  private object Streamable {
+    def bytes(is: java.io.InputStream): Array[Byte] = {
+      val out = new java.io.ByteArrayOutputStream
+      mill.api.IO.stream(is, out)
+      out.close()
+      out.toByteArray
+    }
+  }
+
+  private def intValue(oi: java.util.Optional[Integer], default: Int): Int = {
+    if (oi.isPresent) oi.get().intValue()
+    else default
+  }
+
+  private object PositionMapper {
+    import sbt.util.InterfaceUtil
+
+    private val userCodeStartMarker = "//MILL_USER_CODE_START_MARKER"
+    private val splicedCodeStartMarker = "//MILL_SPLICED_CODE_START_MARKER"
+    private val splicedCodeEndMarker = "//MILL_SPLICED_CODE_END_MARKER"
+
+    /** Transforms positions of problems if coming from a build file. */
+    private def lookup(buildSources: Map[String, xsbti.Position => xsbti.Position])(
+        oldPos: xsbti.Position
+    ): xsbti.Position = {
+      val src = oldPos.sourcePath()
+      if (src.isPresent) {
+        buildSources.get(src.get()) match {
+          case Some(f) => f(oldPos)
+          case _ => oldPos
+        }
+      } else {
+        oldPos
+      }
+    }
+
+    def create(sources: Array[VirtualFile]): (xsbti.Position => xsbti.Position) = {
+      val buildSources0 = {
+        def isBuild(vf: VirtualFile) =
+          mill.main.client.CodeGenConstants.buildFileExtensions.exists(ex =>
+            vf.id().endsWith(s".$ex")
+          )
+
+        sources.collect({
+          case vf if isBuild(vf) =>
+            val str = new String(Streamable.bytes(vf.input()), StandardCharsets.UTF_8)
+
+            val lines = str.linesWithSeparators.toVector
+            val adjustedFile = lines
+              .collectFirst { case s"//MILL_ORIGINAL_FILE_PATH=$rest" => rest.trim }
+              .getOrElse(sys.error(vf.id()))
+
+            vf.id() -> remap(lines, adjustedFile)
+        })
+      }
+
+      if (buildSources0.nonEmpty) lookup(buildSources0.toMap) else null
+    }
+
+    private def remap(
+        lines: Vector[String],
+        adjustedFile: String
+    ): xsbti.Position => xsbti.Position = {
+      val markerLine = lines.indexWhere(_.startsWith(userCodeStartMarker))
+      val splicedMarkerStartLine = lines.indexWhere(_.startsWith(splicedCodeStartMarker))
+      val splicedMarkerLine = lines.indexWhere(_.startsWith(splicedCodeEndMarker))
+      val existsSplicedMarker = splicedMarkerStartLine >= 0 && splicedMarkerLine >= 0
+      val splicedMarkerLineDiff = markerLine + (splicedMarkerLine - splicedMarkerStartLine + 1) + 1
+
+      val topWrapperLen = lines.take(markerLine + 1).map(_.length).sum
+      val splicedMarkerLen =
+        if (existsSplicedMarker) lines.take(splicedMarkerLine + 1).map(_.length).sum
+        else -1
+
+      val originPath = Some(adjustedFile)
+      val originFile = Some(java.nio.file.Paths.get(adjustedFile).toFile)
+
+      def userCode(offset: java.util.Optional[Integer]): Boolean =
+        intValue(offset, -1) > topWrapperLen
+
+      def postSplice(offset: Int): Boolean =
+        existsSplicedMarker && offset > splicedMarkerLen
+
+      def inner(pos0: xsbti.Position): xsbti.Position = {
+        if (userCode(pos0.startOffset()) || userCode(pos0.offset())) {
+          val Array(line, offset, startOffset, endOffset, startLine, endLine) =
+            Array(
+              pos0.line(),
+              pos0.offset(),
+              pos0.startOffset(),
+              pos0.endOffset(),
+              pos0.startLine(),
+              pos0.endLine()
+            )
+              .map(intValue(_, 1) - 1)
+
+          val (baseLine, baseOffset) =
+            if (postSplice(startOffset) || postSplice(offset))
+              (splicedMarkerLineDiff, splicedMarkerLen)
+            else
+              (markerLine, topWrapperLen)
+
+          InterfaceUtil.position(
+            line0 = Some(line - baseLine),
+            content = pos0.lineContent(),
+            offset0 = Some(offset - baseOffset),
+            pointer0 = InterfaceUtil.jo2o(pos0.pointer()),
+            pointerSpace0 = InterfaceUtil.jo2o(pos0.pointerSpace()),
+            sourcePath0 = originPath,
+            sourceFile0 = originFile,
+            startOffset0 = Some(startOffset - baseOffset),
+            endOffset0 = Some(endOffset - baseOffset),
+            startLine0 = Some(startLine - baseLine),
+            startColumn0 = InterfaceUtil.jo2o(pos0.startColumn()),
+            endLine0 = Some(endLine - baseLine),
+            endColumn0 = InterfaceUtil.jo2o(pos0.endColumn())
+          )
+        } else {
+          pos0
+        }
+      }
+
+      inner
+    }
+  }
+
+  private trait ForwardingReporter extends ManagedLoggedReporter {
+    def forwarder: CompileProblemReporter
+    override def logError(problem: xsbti.Problem): Unit = {
+      forwarder.logError(new ZincProblem(problem))
+      super.logError(problem)
+    }
+
+    override def logWarning(problem: xsbti.Problem): Unit = {
+      forwarder.logWarning(new ZincProblem(problem))
+      super.logWarning(problem)
+    }
+
+    override def logInfo(problem: xsbti.Problem): Unit = {
+      forwarder.logInfo(new ZincProblem(problem))
+      super.logInfo(problem)
+    }
+
+    override def printSummary(): Unit = {
+      forwarder.printSummary()
+      super.printSummary()
+    }
+  }
+
+  private trait TransformingReporter extends xsbti.Reporter {
+    def color: Boolean
+    def optPositionMapper: (xsbti.Position => xsbti.Position)
+
+    // Overriding this is necessary because for some reason the LoggedReporter doesn't transform positions
+    // of Actions and DiagnosticRelatedInformation
+    abstract override def log(problem0: xsbti.Problem): Unit = {
+      val localMapper = optPositionMapper
+      val problem = {
+        if (localMapper == null) problem0
+        else TransformingReporter.transformProblem(color, problem0, localMapper)
+      }
+      super.log(problem)
+    }
+  }
+
+  private object TransformingReporter {
+
+    import scala.jdk.CollectionConverters._
+    import sbt.util.InterfaceUtil
+
+    /** implements a transformation that returns the same object if the mapper has no effect. */
+    private def transformProblem(
+        color: Boolean,
+        problem0: xsbti.Problem,
+        mapper: xsbti.Position => xsbti.Position
+    ): xsbti.Problem = {
+      val pos0 = problem0.position()
+      val related0 = problem0.diagnosticRelatedInformation()
+      val actions0 = problem0.actions()
+      val pos = mapper(pos0)
+      val related = transformRelateds(related0, mapper)
+      val actions = transformActions(actions0, mapper)
+      val posIsNew = pos ne pos0
+      if (posIsNew || (related ne related0) || (actions ne actions0)) {
+        val rendered = {
+          // if we transformed the position, then we must re-render the message
+          if (posIsNew) Some(dottyStyleMessage(color, problem0, pos))
+          else InterfaceUtil.jo2o(problem0.rendered())
+        }
+        InterfaceUtil.problem(
+          cat = problem0.category(),
+          pos = pos,
+          msg = problem0.message(),
+          sev = problem0.severity(),
+          rendered = rendered,
+          diagnosticCode = InterfaceUtil.jo2o(problem0.diagnosticCode()),
+          diagnosticRelatedInformation = anyToList(related),
+          actions = anyToList(actions)
+        )
+      }else
+        problem0
+    }
+
+    private type JOrSList[T] = AnyRef
+
+    private def anyToList[T](ts: JOrSList[T]): List[T] = ts match {
+      case ts: List[T] => ts
+      case ts: java.util.List[T] => ts.asScala.toList
+    }
+
+    /** Render the message in the style of dotty */
+    private def dottyStyleMessage(
+        color: Boolean,
+        problem0: xsbti.Problem,
+        pos: xsbti.Position
+    ): String = {
+      val base = problem0.message()
+      val severity = problem0.severity()
+
+      def shade(msg: String) =
+        if (color)
+          severity match {
+            case xsbti.Severity.Error => Console.RED + msg + Console.RESET
+            case xsbti.Severity.Warn => Console.YELLOW + msg + Console.RESET
+            case xsbti.Severity.Info => Console.BLUE + msg + Console.RESET
+          }
+        else msg
+
+      val normCode = {
+        problem0.diagnosticCode().filter(_.code() != "-1").map({ inner =>
+          val prefix = s"[E${inner.code()}] "
+          inner.explanation().map(e =>
+            s"$prefix$e: "
+          ).orElse(prefix)
+        }).orElse("")
+      }
+
+      val optPath = InterfaceUtil.jo2o(pos.sourcePath()).map { path =>
+        val line0 = intValue(pos.line(), -1)
+        val pointer0 = intValue(pos.pointer(), -1)
+        if (line0 >= 0 && pointer0 >= 0)
+          s"$path:$line0:${pointer0 + 1}"
+        else
+          path
+      }
+
+      val normHeader = optPath.map(path =>
+        s"${shade(s"-- $normCode$path")}\n"
+      ).getOrElse("")
+
+      val optSnippet = {
+        val snip = pos.lineContent()
+        val space = pos.pointerSpace().orElse("")
+        val pointer = intValue(pos.pointer(), -99)
+        val endCol = intValue(pos.endColumn(), pointer + 1)
+        if (snip.nonEmpty && space.nonEmpty && pointer >= 0 && endCol >= 0) {
+          val arrowCount = math.max(1, math.min(endCol - pointer, snip.length - space.length))
+          Some(
+            s"""$snip
+               |$space${"^" * arrowCount}""".stripMargin
+          )
+        }else
+          None
+      }
+
+      val content = optSnippet match {
+        case Some(snippet) =>
+          val initial = {
+            s"""$snippet
+               |$base
+               |""".stripMargin
+          }
+          val snippetLine = intValue(pos.line(), -1)
+          if (snippetLine >= 0) {
+            // add margin with line number
+            val lines = initial.linesWithSeparators.toVector
+            val pre = snippetLine.toString
+            val rest0 = " " * pre.length
+            val rest = pre +: Vector.fill(lines.size - 1)(rest0)
+            rest.lazyZip(lines).map((pre, line) => shade(s"$pre │") + line).mkString
+          } else {
+            initial
+          }
+        case None =>
+          base
+      }
+
+      normHeader + content
+    }
+
+    /** Implements a transformation that returns the same list if the mapper has no effect */
+    private def transformActions(
+        actions0: java.util.List[xsbti.Action],
+        mapper: xsbti.Position => xsbti.Position
+    ): JOrSList[xsbti.Action] = {
+      if (actions0.iterator().asScala.exists(a =>
+          a.edit().changes().iterator().asScala.exists(e =>
+            mapper(e.position()) ne e.position()
+          )
+        )
+      ) {
+        actions0.iterator().asScala.map(transformAction(_, mapper)).toList
+      } else {
+        actions0
+      }
+    }
+
+    /** Implements a transformation that returns the same list if the mapper has no effect */
+    private def transformRelateds(
+        related0: java.util.List[xsbti.DiagnosticRelatedInformation],
+        mapper: xsbti.Position => xsbti.Position
+    ): JOrSList[xsbti.DiagnosticRelatedInformation] = {
+
+      if (related0.iterator().asScala.exists(r => mapper(r.position()) ne r.position()))
+        related0.iterator().asScala.map(transformRelated(_, mapper)).toList
+      else
+        related0
+    }
+
+    private def transformRelated(
+        related0: xsbti.DiagnosticRelatedInformation,
+        mapper: xsbti.Position => xsbti.Position
+    ): xsbti.DiagnosticRelatedInformation = {
+      InterfaceUtil.diagnosticRelatedInformation(mapper(related0.position()), related0.message())
+    }
+
+    private def transformAction(
+        action0: xsbti.Action,
+        mapper: xsbti.Position => xsbti.Position
+    ): xsbti.Action = {
+      InterfaceUtil.action(
+        title = action0.title(),
+        description = InterfaceUtil.jo2o(action0.description()),
+        edit = transformEdit(action0.edit(), mapper)
+      )
+    }
+
+    private def transformEdit(
+        edit0: xsbti.WorkspaceEdit,
+        mapper: xsbti.Position => xsbti.Position
+    ): xsbti.WorkspaceEdit = {
+      InterfaceUtil.workspaceEdit(
+        edit0.changes().iterator().asScala.map(transformTEdit(_, mapper)).toList
+      )
+    }
+
+    private def transformTEdit(
+        edit0: xsbti.TextEdit,
+        mapper: xsbti.Position => xsbti.Position
+    ): xsbti.TextEdit = {
+      InterfaceUtil.textEdit(
+        position = mapper(edit0.position()),
+        newText = edit0.newText()
+      )
+    }
+  }
+
   // copied from ModuleUtils
   private def recursive[T <: String](start: T, deps: T => Seq[T]): Seq[T] = {
 
diff --git a/scalanativelib/test/src/mill/scalanativelib/CompileRunTests.scala b/scalanativelib/test/src/mill/scalanativelib/CompileRunTests.scala
index 5c78f4138b77..121080cb3017 100644
--- a/scalanativelib/test/src/mill/scalanativelib/CompileRunTests.scala
+++ b/scalanativelib/test/src/mill/scalanativelib/CompileRunTests.scala
@@ -60,7 +60,7 @@ object CompileRunTests extends TestSuite {
       )
 
       object test extends ScalaNativeTests with TestModule.Utest {
-        override def sources = Task.Sources { millSourcePath / "src/utest" }
+        override def sources = Task.Sources { this.millSourcePath / "src/utest" }
         override def ivyDeps = super.ivyDeps() ++ Agg(
           ivy"com.lihaoyi::utest::$utestVersion"
         )
diff --git a/scalanativelib/test/src/mill/scalanativelib/ExclusionsTests.scala b/scalanativelib/test/src/mill/scalanativelib/ExclusionsTests.scala
index 4947f2962ccd..d3698c0c5877 100644
--- a/scalanativelib/test/src/mill/scalanativelib/ExclusionsTests.scala
+++ b/scalanativelib/test/src/mill/scalanativelib/ExclusionsTests.scala
@@ -1,5 +1,6 @@
 package mill.scalanativelib
 
+import mill.given
 import mill.Agg
 import mill.scalalib._
 import mill.define.Discover
diff --git a/scalanativelib/test/src/mill/scalanativelib/FeaturesTests.scala b/scalanativelib/test/src/mill/scalanativelib/FeaturesTests.scala
index a796c0c9542e..9df8455f8fcb 100644
--- a/scalanativelib/test/src/mill/scalanativelib/FeaturesTests.scala
+++ b/scalanativelib/test/src/mill/scalanativelib/FeaturesTests.scala
@@ -1,5 +1,6 @@
 package mill.scalanativelib
 
+import mill.given
 import mill.define.Discover
 import mill.testkit.UnitTester
 import mill.testkit.TestBaseModule
diff --git a/scalanativelib/test/src/mill/scalanativelib/ScalaTestsErrorTests.scala b/scalanativelib/test/src/mill/scalanativelib/ScalaTestsErrorTests.scala
index e8b948602960..48c9d85a270a 100644
--- a/scalanativelib/test/src/mill/scalanativelib/ScalaTestsErrorTests.scala
+++ b/scalanativelib/test/src/mill/scalanativelib/ScalaTestsErrorTests.scala
@@ -17,7 +17,10 @@ object ScalaTestsErrorTests extends TestSuite {
       }
     }
 
-    override lazy val millDiscover = Discover[this.type]
+    override lazy val millDiscover = {
+      import mill.main.TokenReaders.given
+      Discover[this.type]
+    }
   }
 
   def tests: Tests = Tests {
diff --git a/testkit/src/mill/testkit/IntegrationTester.scala b/testkit/src/mill/testkit/IntegrationTester.scala
index 043b530a5c55..982e2ad672fe 100644
--- a/testkit/src/mill/testkit/IntegrationTester.scala
+++ b/testkit/src/mill/testkit/IntegrationTester.scala
@@ -105,7 +105,7 @@ object IntegrationTester {
        * Returns the raw text of the `.json` metadata file
        */
       def text: String = {
-        val Seq((List(selector), _)) =
+        val Seq((Seq(selector), _)) =
           mill.resolve.ParseArgs.apply(Seq(selector0), SelectMode.Separated).getOrElse(???)
 
         val segments = selector._2.getOrElse(Segments()).value.flatMap(_.pathSegments)
diff --git a/testkit/src/mill/testkit/UnitTester.scala b/testkit/src/mill/testkit/UnitTester.scala
index 90768b2fc134..3740cf3f24f3 100644
--- a/testkit/src/mill/testkit/UnitTester.scala
+++ b/testkit/src/mill/testkit/UnitTester.scala
@@ -189,7 +189,7 @@ class UnitTester(
   }
 
   def close(): Unit = {
-    for ((_, Val(obsolete: AutoCloseable)) <- evaluator.workerCache.values) {
+    for (case (_, Val(obsolete: AutoCloseable)) <- evaluator.workerCache.values) {
       obsolete.close()
     }
   }

From a2e11e6e325133d1ff6f30358bd42e262deec079 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 03:12:52 +0200
Subject: [PATCH 04/13] .

---
 runner/src/mill/runner/MillBuildRootModule.scala | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/runner/src/mill/runner/MillBuildRootModule.scala b/runner/src/mill/runner/MillBuildRootModule.scala
index 10ae284a0af1..c4e9f9d918e9 100644
--- a/runner/src/mill/runner/MillBuildRootModule.scala
+++ b/runner/src/mill/runner/MillBuildRootModule.scala
@@ -243,10 +243,6 @@ abstract class MillBuildRootModule()(implicit
       Seq(
         "-Xplugin:" + lineNumberPluginClasspath().map(_.path).mkString(","),
         "-deprecation",
-        // Make sure we abort of the plugin is not found, to ensure any
-        // classpath/plugin-discovery issues are surfaced early rather than
-        // after hours of debugging
-        "-Xplugin-require:mill-linenumber-plugin"
       )
   }
 

From 300d692acdf91ee2b5e5cae1c3632403c8e35b81 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 03:29:58 +0200
Subject: [PATCH 05/13] .

---
 .../realistic/5-parser/src/Hello.scala        | 32 +++----------------
 1 file changed, 5 insertions(+), 27 deletions(-)

diff --git a/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala b/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala
index 334525b900e0..52df0ce57f67 100644
--- a/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala
+++ b/main/codesig/test/cases/callgraph/realistic/5-parser/src/Hello.scala
@@ -6,15 +6,15 @@ class Word(s: String) extends Phrase
 class Pair(lhs: Phrase, rhs: Phrase) extends Phrase
 
 object Parser {
-  def prefix[_X: P] = P("hello" | "goodbye").!.map(new Word(_))
+  def prefix[$: P] = P("hello" | "goodbye").!.map(new Word(_))
 
-  def suffix[_X: P] = P("world" | "seattle").!.map(new Word(_))
+  def suffix[$: P] = P("world" | "seattle").!.map(new Word(_))
 
-  def ws[_X: P] = P(" ".rep(1))
+  def ws[$: P] = P(" ".rep(1))
 
-  def parened[_X: P] = P("(" ~ parser ~ ")")
+  def parened[$: P] = P("(" ~ parser ~ ")")
 
-  def parser[_X: P]: P[Phrase] = P((parened | prefix) ~ ws ~ (parened | suffix)).map {
+  def parser[$: P]: P[Phrase] = P((parened | prefix) ~ ws ~ (parened | suffix)).map {
     case (lhs, rhs) => new Pair(lhs, rhs)
   }
 }
@@ -24,21 +24,6 @@ object Parser {
     "hello.Parser$#parened(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Parser$#parser(fastparse.ParsingRun)fastparse.ParsingRun"
     ],
-    "hello.Parser$#parse0$proxy8$1(fastparse.ParsingRun)fastparse.ParsingRun": [
-        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
-    ],
-    "hello.Parser$#parse0$proxy9$1(fastparse.ParsingRun)fastparse.ParsingRun": [
-        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
-    ],
-    "hello.Parser$#parse0$proxy9$2(fastparse.ParsingRun)fastparse.ParsingRun": [
-        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
-    ],
-    "hello.Parser$#parse0$proxy9$3(fastparse.ParsingRun)fastparse.ParsingRun": [
-        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
-    ],
-    "hello.Parser$#parse0$proxy9$4(fastparse.ParsingRun)fastparse.ParsingRun": [
-        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
-    ],
     "hello.Parser$#parser(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Pair#<init>(hello.Phrase,hello.Phrase)void",
         "hello.Parser$#parened(fastparse.ParsingRun)fastparse.ParsingRun",
@@ -49,16 +34,9 @@ object Parser {
     "hello.Parser$#prefix(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Word#<init>(java.lang.String)void"
     ],
-    "hello.Parser$#rec$1(fastparse.ParsingRun,int,fastparse.Implicits$Repeater,java.lang.Object,fastparse.ParsingRun,int,int,boolean,boolean,fastparse.internal.Msgs,fastparse.internal.Msgs)fastparse.ParsingRun": [
-        "hello.Parser$#end$1(int,fastparse.ParsingRun,fastparse.Implicits$Repeater,java.lang.Object,int,int,int,boolean)fastparse.ParsingRun",
-        "hello.Parser$#parse0$1$1(fastparse.ParsingRun)fastparse.ParsingRun"
-    ],
     "hello.Parser$#suffix(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Word#<init>(java.lang.String)void"
     ],
-    "hello.Parser$#ws(fastparse.ParsingRun)fastparse.ParsingRun": [
-        "hello.Parser$#rec$1(fastparse.ParsingRun,int,fastparse.Implicits$Repeater,java.lang.Object,fastparse.ParsingRun,int,int,boolean,boolean,fastparse.internal.Msgs,fastparse.internal.Msgs)fastparse.ParsingRun"
-    ],
     "hello.Parser.parened(fastparse.ParsingRun)fastparse.ParsingRun": [
         "hello.Parser$#<init>()void",
         "hello.Parser$#parened(fastparse.ParsingRun)fastparse.ParsingRun"

From 3eb4c8257d0d49ec52abef3a9beeb5d4c0e2027e Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 03:32:19 +0200
Subject: [PATCH 06/13] .

---
 .../multi-level-editing/src/MultiLevelBuildTests.scala | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala b/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
index c799d0f65876..2f293f7cbf84 100644
--- a/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
+++ b/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
@@ -336,7 +336,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         // Ensure the file path in the compile error is properly adjusted to point
         // at the original source file and not the generated file
         (workspacePath / "build.mill").toString,
-        "Not found: doesnt"
+        "Not found: value doesnt"
       )
       checkWatchedFiles(tester, Nil, buildPaths(tester), buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, false, false)
@@ -346,7 +346,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/build.mill").toString,
-        "Not found: doesnt"
+        "Not found: object doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, false)
@@ -356,7 +356,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/mill-build/build.mill").toString,
-        "Not found: doesnt"
+        "Not found: object doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, Nil, buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, null)
@@ -366,7 +366,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/build.mill").toString,
-        "Not found: doesnt"
+        "Not found: object doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, true)
@@ -376,7 +376,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "build.mill").toString,
-        "Not found: doesnt"
+        "Not found: value doesnt"
       )
       checkWatchedFiles(tester, Nil, buildPaths(tester), buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, true, false)

From e32cc077996d76e291e3291e639093a133bb11e8 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 03:36:20 +0200
Subject: [PATCH 07/13] .

---
 .../multi-level-editing/src/MultiLevelBuildTests.scala | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala b/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
index 2f293f7cbf84..7c92a4486d49 100644
--- a/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
+++ b/integration/invalidation/multi-level-editing/src/MultiLevelBuildTests.scala
@@ -336,7 +336,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         // Ensure the file path in the compile error is properly adjusted to point
         // at the original source file and not the generated file
         (workspacePath / "build.mill").toString,
-        "Not found: value doesnt"
+        "not found: value doesnt"
       )
       checkWatchedFiles(tester, Nil, buildPaths(tester), buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, false, false)
@@ -346,7 +346,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/build.mill").toString,
-        "Not found: object doesnt"
+        "not found: object doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, false)
@@ -356,7 +356,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/mill-build/build.mill").toString,
-        "Not found: object doesnt"
+        "not found: object doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, Nil, buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, null)
@@ -366,7 +366,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "mill-build/build.mill").toString,
-        "Not found: object doesnt"
+        "not found: object doesnt"
       )
       checkWatchedFiles(tester, Nil, Nil, buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, null, true)
@@ -376,7 +376,7 @@ object MultiLevelBuildTests extends UtestIntegrationTestSuite {
         tester,
         "\n1 tasks failed",
         (workspacePath / "build.mill").toString,
-        "Not found: value doesnt"
+        "not found: value doesnt"
       )
       checkWatchedFiles(tester, Nil, buildPaths(tester), buildPaths2(tester), buildPaths3(tester))
       checkChangedClassloaders(tester, null, null, true, false)

From 6f6d9f808b025b96b145cfa60de82001b3e3dc2a Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 03:36:56 +0200
Subject: [PATCH 08/13] .

---
 example/thirdparty/mockito/build.mill | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/example/thirdparty/mockito/build.mill b/example/thirdparty/mockito/build.mill
index 9eab3b2ab0be..ad0fbf5e3b11 100644
--- a/example/thirdparty/mockito/build.mill
+++ b/example/thirdparty/mockito/build.mill
@@ -43,7 +43,7 @@ trait MockitoModule extends MavenModule{
   def testFramework = "com.novocode.junit.JUnitFramework"
   def testForkArgs: T[Seq[String]] = Seq.empty[String]
 
-  def testFilteredSources: T[Seq[PathRef]] = Task { Seq.empty }
+  def testFilteredSources: T[Seq[PathRef]] = Task { Seq.empty[PathRef] }
 
   object test extends MavenTests{
     def moduleDeps = super.moduleDeps ++ MockitoModule.this.testModuleDeps

From c7e263103452a59c4517a42795bb3e69c41afc52 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 04:20:06 +0200
Subject: [PATCH 09/13] .

---
 .../linenumbers/resources/scalac-plugin.xml   |   4 +
 .../linenumbers/LineNumberCorrector.scala     |  65 +++
 .../mill/linenumbers/LineNumberPlugin.scala   |  44 ++
 .../src/mill/runner/MillBuildRootModule.scala |   4 +
 .../mill/scalalib/worker/ZincWorkerImpl.scala | 411 ++----------------
 5 files changed, 143 insertions(+), 385 deletions(-)
 create mode 100644 runner/linenumbers/resources/scalac-plugin.xml
 create mode 100644 runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala
 create mode 100644 runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala

diff --git a/runner/linenumbers/resources/scalac-plugin.xml b/runner/linenumbers/resources/scalac-plugin.xml
new file mode 100644
index 000000000000..7a27d92f3f79
--- /dev/null
+++ b/runner/linenumbers/resources/scalac-plugin.xml
@@ -0,0 +1,4 @@
+<plugin>
+    <name>mill-linenumber-plugin</name>
+    <classname>mill.linenumbers.LineNumberPlugin</classname>
+</plugin>
\ No newline at end of file
diff --git a/runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala b/runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala
new file mode 100644
index 000000000000..74fa588f9e3c
--- /dev/null
+++ b/runner/linenumbers/src/mill/linenumbers/LineNumberCorrector.scala
@@ -0,0 +1,65 @@
+package mill.linenumbers
+
+import scala.tools.nsc.Global
+
+object LineNumberCorrector {
+  def apply(
+      g: Global,
+      lines: Seq[String],
+      adjustedFile: String
+  )(unit: g.CompilationUnit): g.Tree = {
+
+    val userCodeStartMarker = "//MILL_USER_CODE_START_MARKER"
+
+    import scala.reflect.internal.util._
+
+    val markerLine = lines.indexWhere(_.startsWith(userCodeStartMarker))
+
+    val topWrapperLen = lines.take(markerLine + 1).map(_.length).sum
+
+    val trimmedSource = new BatchSourceFile(
+      new scala.reflect.io.PlainFile(adjustedFile),
+      g.currentSource.content.drop(topWrapperLen)
+    )
+
+    import scala.reflect.internal.util._
+    object Transformer extends g.Transformer {
+      override def transform(tree: g.Tree) = {
+        val transformedTree = super.transform(tree)
+        // The `start` and `end` values in transparent/range positions are left
+        // untouched, because of some aggressive validation in scalac that checks
+        // that trees are not overlapping, and shifting these values here
+        // violates the invariant (which breaks Ammonite, potentially because
+        // of multi-stage).
+        // Moreover, we rely only on the "point" value (for error reporting).
+        // The ticket https://github.com/scala/scala-dev/issues/390 tracks down
+        // relaxing the aggressive validation.
+        val newPos = tree.pos match {
+          case s: TransparentPosition if s.start > topWrapperLen =>
+            new TransparentPosition(
+              trimmedSource,
+              s.start - topWrapperLen,
+              s.point - topWrapperLen,
+              s.end - topWrapperLen
+            )
+          case s: RangePosition if s.start > topWrapperLen =>
+            new RangePosition(
+              trimmedSource,
+              s.start - topWrapperLen,
+              s.point - topWrapperLen,
+              s.end - topWrapperLen
+            )
+          case s: OffsetPosition if s.start > topWrapperLen =>
+            new OffsetPosition(trimmedSource, s.point - topWrapperLen)
+          case s => s
+
+        }
+        transformedTree.pos = newPos
+
+        transformedTree
+      }
+    }
+    Transformer.transform(unit.body)
+  }
+
+}
diff --git a/runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala b/runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala
new file mode 100644
index 000000000000..b8f0aeee877a
--- /dev/null
+++ b/runner/linenumbers/src/mill/linenumbers/LineNumberPlugin.scala
@@ -0,0 +1,44 @@
+package mill.linenumbers
+
+import mill.main.client.CodeGenConstants.buildFileExtensions
+import scala.tools.nsc._
+import scala.tools.nsc.plugins.{Plugin, PluginComponent}
+
+/**
+ * Used to capture the names in scope after every execution, reporting them
+ * to the `output` function. Needs to be a compiler plugin so we can hook in
+ * immediately after the `typer`
+ */
+class LineNumberPlugin(val global: Global) extends Plugin {
+  override def init(options: List[String], error: String => Unit): Boolean = true
+  val name: String = "mill-linenumber-plugin"
+  val description = "Adjusts line numbers in the user-provided script to compensate for wrapping"
+  val components: List[PluginComponent] = List(
+    new PluginComponent {
+      val global = LineNumberPlugin.this.global
+      val runsAfter = List("parser")
+      val phaseName = "FixLineNumbers"
+      def newPhase(prev: Phase): Phase = new global.GlobalPhase(prev) {
+        def name = phaseName
+        def apply(unit: global.CompilationUnit): Unit = {
+          LineNumberPlugin.apply(global)(unit)
+        }
+      }
+    }
+  )
+}
+
+object LineNumberPlugin {
+  def apply(g: Global)(unit: g.CompilationUnit): Unit = {
+    if (buildFileExtensions.exists(ex => g.currentSource.file.name.endsWith(s".$ex"))) {
+
+      val str = new String(g.currentSource.content)
+      val lines = str.linesWithSeparators.toVector
+      val adjustedFile = lines
+        .collectFirst { case s"//MILL_ORIGINAL_FILE_PATH=$rest" => rest.trim }
+        .getOrElse(sys.error(g.currentSource.path))
+
+      unit.body = LineNumberCorrector(g, lines, adjustedFile)(unit)
+    }
+  }
+}
diff --git a/runner/src/mill/runner/MillBuildRootModule.scala b/runner/src/mill/runner/MillBuildRootModule.scala
index c4e9f9d918e9..10ae284a0af1 100644
--- a/runner/src/mill/runner/MillBuildRootModule.scala
+++ b/runner/src/mill/runner/MillBuildRootModule.scala
@@ -243,6 +243,10 @@ abstract class MillBuildRootModule()(implicit
       Seq(
         "-Xplugin:" + lineNumberPluginClasspath().map(_.path).mkString(","),
         "-deprecation",
+        // Make sure we abort of the plugin is not found, to ensure any
+        // classpath/plugin-discovery issues are surfaced early rather than
+        // after hours of debugging
+        "-Xplugin-require:mill-linenumber-plugin"
       )
   }
 
diff --git a/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala b/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
index 7b53632afd8d..5b7c373992a2 100644
--- a/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
+++ b/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
@@ -42,7 +42,6 @@ import xsbti.compile.{
 import xsbti.{PathBasedFile, VirtualFile}
 
 import java.io.{File, PrintWriter}
-import java.nio.charset.StandardCharsets
 import java.util.Optional
 import scala.annotation.tailrec
 import scala.collection.mutable
@@ -145,7 +144,7 @@ class ZincWorkerImpl(
       compilerClasspath,
       scalacPluginClasspath,
       Seq()
-    ) { (compilers: Compilers) =>
+    ) { compilers: Compilers =>
       if (ZincWorkerUtil.isDotty(scalaVersion) || ZincWorkerUtil.isScala3Milestone(scalaVersion)) {
         // dotty 0.x and scala 3 milestones use the dotty-doc tool
         val dottydocClass =
@@ -389,7 +388,7 @@ class ZincWorkerImpl(
       compilerClasspath = compilerClasspath,
       scalacPluginClasspath = scalacPluginClasspath,
       javacOptions = javacOptions
-    ) { (compilers: Compilers) =>
+    ) { compilers: Compilers =>
       compileInternal(
         upstreamCompileOutput = upstreamCompileOutput,
         sources = sources,
@@ -496,8 +495,6 @@ class ZincWorkerImpl(
       auxiliaryClassFileExtensions: Seq[String],
       zincCache: os.SubPath = os.sub / "zinc"
   )(implicit ctx: ZincWorkerApi.Ctx): Result[CompilationResult] = {
-    import ZincWorkerImpl.{ForwardingReporter, TransformingReporter, PositionMapper}
-
     os.makeDir.all(ctx.dest)
 
     val classesDir =
@@ -528,21 +525,30 @@ class ZincWorkerImpl(
     val loggerId = Thread.currentThread().getId.toString
     val logger = SbtLoggerUtils.createLogger(loggerId, consoleAppender, zincLogLevel)
 
-    def mkNewReporter(mapper: (xsbti.Position => xsbti.Position)) = reporter match {
-      case None =>
-        new ManagedLoggedReporter(10, logger) with RecordingReporter
-          with TransformingReporter {
-          def color: Boolean = ctx.log.colored
-          def optPositionMapper = mapper
-        }
-      case Some(forwarder0) =>
-        new ManagedLoggedReporter(10, logger)
-          with ForwardingReporter
-          with RecordingReporter
-          with TransformingReporter {
-          def forwarder = forwarder0
-          def color: Boolean = ctx.log.colored
-          def optPositionMapper = mapper
+    val newReporter = reporter match {
+      case None => new ManagedLoggedReporter(10, logger) with RecordingReporter
+      case Some(forwarder) =>
+        new ManagedLoggedReporter(10, logger) with RecordingReporter {
+
+          override def logError(problem: xsbti.Problem): Unit = {
+            forwarder.logError(new ZincProblem(problem))
+            super.logError(problem)
+          }
+
+          override def logWarning(problem: xsbti.Problem): Unit = {
+            forwarder.logWarning(new ZincProblem(problem))
+            super.logWarning(problem)
+          }
+
+          override def logInfo(problem: xsbti.Problem): Unit = {
+            forwarder.logInfo(new ZincProblem(problem))
+            super.logInfo(problem)
+          }
+
+          override def printSummary(): Unit = {
+            forwarder.printSummary()
+            super.printSummary()
+          }
         }
     }
     val analysisMap0 = upstreamCompileOutput.map(c => c.classes.path -> c.analysisFile).toMap
@@ -575,10 +581,6 @@ class ZincWorkerImpl(
       auxiliaryClassFileExtensions.map(new AuxiliaryClassFileExtension(_)).toArray
     )
 
-    val newReporter = mkNewReporter(
-      PositionMapper.create(virtualSources)
-    )
-
     val inputs = ic.inputs(
       classpath = classpath,
       sources = virtualSources,
@@ -671,367 +673,6 @@ class ZincWorkerImpl(
 }
 
 object ZincWorkerImpl {
-
-  /**
-   * TODO: copied from mill.scalalib.Assembly
-   */
-  private object Streamable {
-    def bytes(is: java.io.InputStream): Array[Byte] = {
-      val out = new java.io.ByteArrayOutputStream
-      mill.api.IO.stream(is, out)
-      out.close()
-      out.toByteArray
-    }
-  }
-
-  private def intValue(oi: java.util.Optional[Integer], default: Int): Int = {
-    if (oi.isPresent) oi.get().intValue()
-    else default
-  }
-
-  private object PositionMapper {
-    import sbt.util.InterfaceUtil
-
-    private val userCodeStartMarker = "//MILL_USER_CODE_START_MARKER"
-    private val splicedCodeStartMarker = "//MILL_SPLICED_CODE_START_MARKER"
-    private val splicedCodeEndMarker = "//MILL_SPLICED_CODE_END_MARKER"
-
-    /** Transforms positions of problems if coming from a build file. */
-    private def lookup(buildSources: Map[String, xsbti.Position => xsbti.Position])(
-        oldPos: xsbti.Position
-    ): xsbti.Position = {
-      val src = oldPos.sourcePath()
-      if (src.isPresent) {
-        buildSources.get(src.get()) match {
-          case Some(f) => f(oldPos)
-          case _ => oldPos
-        }
-      } else {
-        oldPos
-      }
-    }
-
-    def create(sources: Array[VirtualFile]): (xsbti.Position => xsbti.Position) = {
-      val buildSources0 = {
-        def isBuild(vf: VirtualFile) =
-          mill.main.client.CodeGenConstants.buildFileExtensions.exists(ex =>
-            vf.id().endsWith(s".$ex")
-          )
-
-        sources.collect({
-          case vf if isBuild(vf) =>
-            val str = new String(Streamable.bytes(vf.input()), StandardCharsets.UTF_8)
-
-            val lines = str.linesWithSeparators.toVector
-            val adjustedFile = lines
-              .collectFirst { case s"//MILL_ORIGINAL_FILE_PATH=$rest" => rest.trim }
-              .getOrElse(sys.error(vf.id()))
-
-            vf.id() -> remap(lines, adjustedFile)
-        })
-      }
-
-      if (buildSources0.nonEmpty) lookup(buildSources0.toMap) else null
-    }
-
-    private def remap(
-        lines: Vector[String],
-        adjustedFile: String
-    ): xsbti.Position => xsbti.Position = {
-      val markerLine = lines.indexWhere(_.startsWith(userCodeStartMarker))
-      val splicedMarkerStartLine = lines.indexWhere(_.startsWith(splicedCodeStartMarker))
-      val splicedMarkerLine = lines.indexWhere(_.startsWith(splicedCodeEndMarker))
-      val existsSplicedMarker = splicedMarkerStartLine >= 0 && splicedMarkerLine >= 0
-      val splicedMarkerLineDiff = markerLine + (splicedMarkerLine - splicedMarkerStartLine + 1) + 1
-
-      val topWrapperLen = lines.take(markerLine + 1).map(_.length).sum
-      val splicedMarkerLen =
-        if (existsSplicedMarker) lines.take(splicedMarkerLine + 1).map(_.length).sum
-        else -1
-
-      val originPath = Some(adjustedFile)
-      val originFile = Some(java.nio.file.Paths.get(adjustedFile).toFile)
-
-      def userCode(offset: java.util.Optional[Integer]): Boolean =
-        intValue(offset, -1) > topWrapperLen
-
-      def postSplice(offset: Int): Boolean =
-        existsSplicedMarker && offset > splicedMarkerLen
-
-      def inner(pos0: xsbti.Position): xsbti.Position = {
-        if (userCode(pos0.startOffset()) || userCode(pos0.offset())) {
-          val Array(line, offset, startOffset, endOffset, startLine, endLine) =
-            Array(
-              pos0.line(),
-              pos0.offset(),
-              pos0.startOffset(),
-              pos0.endOffset(),
-              pos0.startLine(),
-              pos0.endLine()
-            )
-              .map(intValue(_, 1) - 1)
-
-          val (baseLine, baseOffset) =
-            if (postSplice(startOffset) || postSplice(offset))
-              (splicedMarkerLineDiff, splicedMarkerLen)
-            else
-              (markerLine, topWrapperLen)
-
-          InterfaceUtil.position(
-            line0 = Some(line - baseLine),
-            content = pos0.lineContent(),
-            offset0 = Some(offset - baseOffset),
-            pointer0 = InterfaceUtil.jo2o(pos0.pointer()),
-            pointerSpace0 = InterfaceUtil.jo2o(pos0.pointerSpace()),
-            sourcePath0 = originPath,
-            sourceFile0 = originFile,
-            startOffset0 = Some(startOffset - baseOffset),
-            endOffset0 = Some(endOffset - baseOffset),
-            startLine0 = Some(startLine - baseLine),
-            startColumn0 = InterfaceUtil.jo2o(pos0.startColumn()),
-            endLine0 = Some(endLine - baseLine),
-            endColumn0 = InterfaceUtil.jo2o(pos0.endColumn())
-          )
-        } else {
-          pos0
-        }
-      }
-
-      inner
-    }
-  }
-
-  private trait ForwardingReporter extends ManagedLoggedReporter {
-    def forwarder: CompileProblemReporter
-    override def logError(problem: xsbti.Problem): Unit = {
-      forwarder.logError(new ZincProblem(problem))
-      super.logError(problem)
-    }
-
-    override def logWarning(problem: xsbti.Problem): Unit = {
-      forwarder.logWarning(new ZincProblem(problem))
-      super.logWarning(problem)
-    }
-
-    override def logInfo(problem: xsbti.Problem): Unit = {
-      forwarder.logInfo(new ZincProblem(problem))
-      super.logInfo(problem)
-    }
-
-    override def printSummary(): Unit = {
-      forwarder.printSummary()
-      super.printSummary()
-    }
-  }
-
-  private trait TransformingReporter extends xsbti.Reporter {
-    def color: Boolean
-    def optPositionMapper: (xsbti.Position => xsbti.Position)
-
-    // Overriding this is necessary because for some reason the LoggedReporter doesn't transform positions
-    // of Actions and DiagnosticRelatedInformation
-    abstract override def log(problem0: xsbti.Problem): Unit = {
-      val localMapper = optPositionMapper
-      val problem = {
-        if (localMapper == null) problem0
-        else TransformingReporter.transformProblem(color, problem0, localMapper)
-      }
-      super.log(problem)
-    }
-  }
-
-  private object TransformingReporter {
-
-    import scala.jdk.CollectionConverters._
-    import sbt.util.InterfaceUtil
-
-    /** implements a transformation that returns the same object if the mapper has no effect. */
-    private def transformProblem(
-        color: Boolean,
-        problem0: xsbti.Problem,
-        mapper: xsbti.Position => xsbti.Position
-    ): xsbti.Problem = {
-      val pos0 = problem0.position()
-      val related0 = problem0.diagnosticRelatedInformation()
-      val actions0 = problem0.actions()
-      val pos = mapper(pos0)
-      val related = transformRelateds(related0, mapper)
-      val actions = transformActions(actions0, mapper)
-      val posIsNew = pos ne pos0
-      if (posIsNew || (related ne related0) || (actions ne actions0)) {
-        val rendered = {
-          // if we transformed the position, then we must re-render the message
-          if (posIsNew) Some(dottyStyleMessage(color, problem0, pos))
-          else InterfaceUtil.jo2o(problem0.rendered())
-        }
-        InterfaceUtil.problem(
-          cat = problem0.category(),
-          pos = pos,
-          msg = problem0.message(),
-          sev = problem0.severity(),
-          rendered = rendered,
-          diagnosticCode = InterfaceUtil.jo2o(problem0.diagnosticCode()),
-          diagnosticRelatedInformation = anyToList(related),
-          actions = anyToList(actions)
-        )
-      }else
-        problem0
-    }
-
-    private type JOrSList[T] = AnyRef
-
-    private def anyToList[T](ts: JOrSList[T]): List[T] = ts match {
-      case ts: List[T] => ts
-      case ts: java.util.List[T] => ts.asScala.toList
-    }
-
-    /** Render the message in the style of dotty */
-    private def dottyStyleMessage(
-        color: Boolean,
-        problem0: xsbti.Problem,
-        pos: xsbti.Position
-    ): String = {
-      val base = problem0.message()
-      val severity = problem0.severity()
-
-      def shade(msg: String) =
-        if (color)
-          severity match {
-            case xsbti.Severity.Error => Console.RED + msg + Console.RESET
-            case xsbti.Severity.Warn => Console.YELLOW + msg + Console.RESET
-            case xsbti.Severity.Info => Console.BLUE + msg + Console.RESET
-          }
-        else msg
-
-      val normCode = {
-        problem0.diagnosticCode().filter(_.code() != "-1").map({ inner =>
-          val prefix = s"[E${inner.code()}] "
-          inner.explanation().map(e =>
-            s"$prefix$e: "
-          ).orElse(prefix)
-        }).orElse("")
-      }
-
-      val optPath = InterfaceUtil.jo2o(pos.sourcePath()).map { path =>
-        val line0 = intValue(pos.line(), -1)
-        val pointer0 = intValue(pos.pointer(), -1)
-        if (line0 >= 0 && pointer0 >= 0)
-          s"$path:$line0:${pointer0 + 1}"
-        else
-          path
-      }
-
-      val normHeader = optPath.map(path =>
-        s"${shade(s"-- $normCode$path")}\n"
-      ).getOrElse("")
-
-      val optSnippet = {
-        val snip = pos.lineContent()
-        val space = pos.pointerSpace().orElse("")
-        val pointer = intValue(pos.pointer(), -99)
-        val endCol = intValue(pos.endColumn(), pointer + 1)
-        if (snip.nonEmpty && space.nonEmpty && pointer >= 0 && endCol >= 0) {
-          val arrowCount = math.max(1, math.min(endCol - pointer, snip.length - space.length))
-          Some(
-            s"""$snip
-               |$space${"^" * arrowCount}""".stripMargin
-          )
-        }else
-          None
-      }
-
-      val content = optSnippet match {
-        case Some(snippet) =>
-          val initial = {
-            s"""$snippet
-               |$base
-               |""".stripMargin
-          }
-          val snippetLine = intValue(pos.line(), -1)
-          if (snippetLine >= 0) {
-            // add margin with line number
-            val lines = initial.linesWithSeparators.toVector
-            val pre = snippetLine.toString
-            val rest0 = " " * pre.length
-            val rest = pre +: Vector.fill(lines.size - 1)(rest0)
-            rest.lazyZip(lines).map((pre, line) => shade(s"$pre │") + line).mkString
-          } else {
-            initial
-          }
-        case None =>
-          base
-      }
-
-      normHeader + content
-    }
-
-    /** Implements a transformation that returns the same list if the mapper has no effect */
-    private def transformActions(
-        actions0: java.util.List[xsbti.Action],
-        mapper: xsbti.Position => xsbti.Position
-    ): JOrSList[xsbti.Action] = {
-      if (actions0.iterator().asScala.exists(a =>
-          a.edit().changes().iterator().asScala.exists(e =>
-            mapper(e.position()) ne e.position()
-          )
-        )
-      ) {
-        actions0.iterator().asScala.map(transformAction(_, mapper)).toList
-      } else {
-        actions0
-      }
-    }
-
-    /** Implements a transformation that returns the same list if the mapper has no effect */
-    private def transformRelateds(
-        related0: java.util.List[xsbti.DiagnosticRelatedInformation],
-        mapper: xsbti.Position => xsbti.Position
-    ): JOrSList[xsbti.DiagnosticRelatedInformation] = {
-
-      if (related0.iterator().asScala.exists(r => mapper(r.position()) ne r.position()))
-        related0.iterator().asScala.map(transformRelated(_, mapper)).toList
-      else
-        related0
-    }
-
-    private def transformRelated(
-        related0: xsbti.DiagnosticRelatedInformation,
-        mapper: xsbti.Position => xsbti.Position
-    ): xsbti.DiagnosticRelatedInformation = {
-      InterfaceUtil.diagnosticRelatedInformation(mapper(related0.position()), related0.message())
-    }
-
-    private def transformAction(
-        action0: xsbti.Action,
-        mapper: xsbti.Position => xsbti.Position
-    ): xsbti.Action = {
-      InterfaceUtil.action(
-        title = action0.title(),
-        description = InterfaceUtil.jo2o(action0.description()),
-        edit = transformEdit(action0.edit(), mapper)
-      )
-    }
-
-    private def transformEdit(
-        edit0: xsbti.WorkspaceEdit,
-        mapper: xsbti.Position => xsbti.Position
-    ): xsbti.WorkspaceEdit = {
-      InterfaceUtil.workspaceEdit(
-        edit0.changes().iterator().asScala.map(transformTEdit(_, mapper)).toList
-      )
-    }
-
-    private def transformTEdit(
-        edit0: xsbti.TextEdit,
-        mapper: xsbti.Position => xsbti.Position
-    ): xsbti.TextEdit = {
-      InterfaceUtil.textEdit(
-        position = mapper(edit0.position()),
-        newText = edit0.newText()
-      )
-    }
-  }
-
   // copied from ModuleUtils
   private def recursive[T <: String](start: T, deps: T => Seq[T]): Seq[T] = {
 

From a31128d9ddf88fcf1841749c5b5cdcdf369848b7 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 04:27:51 +0200
Subject: [PATCH 10/13] .

---
 .../feature/docannotations/src/DocAnnotationsTests.scala        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/integration/feature/docannotations/src/DocAnnotationsTests.scala b/integration/feature/docannotations/src/DocAnnotationsTests.scala
index 4ef2900e86c7..ee3449a00ea8 100644
--- a/integration/feature/docannotations/src/DocAnnotationsTests.scala
+++ b/integration/feature/docannotations/src/DocAnnotationsTests.scala
@@ -93,7 +93,7 @@ object DocAnnotationsTests extends UtestIntegrationTestSuite {
 
       assert(
         globMatches(
-          """core.ivyDepsTree(JavaModule.scala:896)
+          """core.ivyDepsTree(JavaModule.scala:...)
             |    Command to print the transitive dependency tree to STDOUT.
             |
             |    --inverse                Invert the tree representation, so that the root is on the bottom val

From 662c117f1bc39787b6c4967be170bb737c6796fb Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 04:37:34 +0200
Subject: [PATCH 11/13] .

---
 contrib/playlib/src/mill/playlib/RouterModule.scala           | 2 +-
 contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala | 4 ++--
 contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/contrib/playlib/src/mill/playlib/RouterModule.scala b/contrib/playlib/src/mill/playlib/RouterModule.scala
index 67123db1df07..11b921257b5d 100644
--- a/contrib/playlib/src/mill/playlib/RouterModule.scala
+++ b/contrib/playlib/src/mill/playlib/RouterModule.scala
@@ -81,7 +81,7 @@ trait RouterModule extends ScalaModule with Version {
       artifactSuffix = playMinorVersion() match {
         case "2.6" => "_2.12"
         case "2.7" | "2.8" => "_2.13"
-        case _ => "_3"
+        case _ => "_2.13"
       }
     )
   }
diff --git a/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala b/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
index c50199b2f862..718ddf27670e 100644
--- a/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
+++ b/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
@@ -71,7 +71,7 @@ object RouterModuleTests extends TestSuite with PlayTestSuite {
             val eitherResult = eval.apply(project.compileRouter)
             val Left(Failure(message, x)) = eitherResult
             val playExpectedMessage =
-              if (!playVersion.startsWith("2.7.") && !playVersion.startsWith("2.8.")) {
+              if (playVersion.startsWith("2.6.")) {
                 "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
               } else {
                 "end of input expected"
@@ -98,7 +98,7 @@ object RouterModuleTests extends TestSuite with PlayTestSuite {
             val eitherResult = eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
             val Left(Failure(message, x)) = eitherResult
             val playExpectedMessage =
-              if (!playVersion.startsWith("2.7.") && !playVersion.startsWith("2.8.")) {
+              if (playVersion.startsWith("2.6.")) {
                 "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
               } else {
                 "end of input expected"
diff --git a/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala b/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
index d881936fab24..36b0b02c0634 100644
--- a/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
+++ b/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
@@ -168,9 +168,9 @@ object HelloWorldTests1_5 extends HelloWorldTests {
 }
 object HelloWorldTests1_6 extends HelloWorldTests {
   override val testTwirlVersion = "1.6.2"
-  override val wildcard = "*"
+  override val wildcard = "_"
 }
 object HelloWorldTests2_0 extends HelloWorldTests {
   override val testTwirlVersion = "2.0.1"
-  override val wildcard = "*"
+  override val wildcard = "_"
 }

From b3cc906d828c932aff5ecb6ec819fb6fc3df0555 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 07:02:35 +0200
Subject: [PATCH 12/13] .

---
 main/api/src/mill/api/AggWrapper.scala           | 6 +++---
 main/resolve/src/mill/resolve/ExpandBraces.scala | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/main/api/src/mill/api/AggWrapper.scala b/main/api/src/mill/api/AggWrapper.scala
index 31f27082915b..9be41fb579b3 100644
--- a/main/api/src/mill/api/AggWrapper.scala
+++ b/main/api/src/mill/api/AggWrapper.scala
@@ -33,11 +33,11 @@ private[mill] sealed class AggWrapper(strictUniqueness: Boolean) {
     def map[T](f: V => T): Agg[T]
     def filter(f: V => Boolean): Agg[V]
 
-    override def collect[T](f: PartialFunction[V, T]): Agg[T] = super.collect(f)
-    override def zipWithIndex: Agg[(V, Int)] = super.zipWithIndex
+    def collect[T](f: PartialFunction[V, T]): Agg[T]
+    def zipWithIndex: Agg[(V, Int)]
     def reverse: Agg[V]
     def zip[T](other: Agg[T]): Agg[(V, T)]
-    // def ++[T >: V](other: IterableOnce[T]): Agg[T] // error overriding final method ++ in trait IterableOps
+    def ++[T >: V](other: IterableOnce[T]): Agg[T]
     def length: Int
     def isEmpty: Boolean
     def foreach[U](f: V => U): Unit
diff --git a/main/resolve/src/mill/resolve/ExpandBraces.scala b/main/resolve/src/mill/resolve/ExpandBraces.scala
index fdef17c5a1f1..b0d7dc4ecbb6 100644
--- a/main/resolve/src/mill/resolve/ExpandBraces.scala
+++ b/main/resolve/src/mill/resolve/ExpandBraces.scala
@@ -10,7 +10,7 @@ private object ExpandBraces {
     case class Expand(values: List[List[Fragment]]) extends Fragment
   }
 
-  private[ExpandBraces] def expandRec(frags: List[Fragment]): List[List[String]] = frags match {
+  def expandRec(frags: List[Fragment]): List[List[String]] = frags match {
     case Nil => List(List())
     case head :: tail =>
       val tailStrings = expandRec(tail)

From b9806501ed062c356a4eb991c0a2649f358c81f9 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sat, 12 Oct 2024 07:55:23 +0200
Subject: [PATCH 13/13] .

---
 bsp/src/mill/bsp/BSP.scala       | 2 +-
 idea/src/mill/idea/GenIdea.scala | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/bsp/src/mill/bsp/BSP.scala b/bsp/src/mill/bsp/BSP.scala
index 285383bb8758..4eea72bc9b33 100644
--- a/bsp/src/mill/bsp/BSP.scala
+++ b/bsp/src/mill/bsp/BSP.scala
@@ -1,7 +1,7 @@
 package mill.bsp
 
 import mill.api.{Ctx, PathRef}
-import mill.{Agg, T, Task, given}
+import mill.{Agg, T, Task}
 import mill.define.{Command, Discover, ExternalModule}
 import mill.main.BuildInfo
 import mill.eval.Evaluator
diff --git a/idea/src/mill/idea/GenIdea.scala b/idea/src/mill/idea/GenIdea.scala
index 66c3f76224db..31b7fab6ebe2 100644
--- a/idea/src/mill/idea/GenIdea.scala
+++ b/idea/src/mill/idea/GenIdea.scala
@@ -1,6 +1,5 @@
 package mill.idea
 
-import mill.given
 import mill.Task
 import mill.api.Result
 import mill.define.{Command, Discover, ExternalModule}