Quit flag not suppresses compilation errors

modules/build/src/main/scala/scala/build/ConsoleBloopBuildClient.scala

@@ -183,7 +183,7 @@ object ConsoleBloopBuildClient {
           "." + File.separator + p.relativeTo(Os.pwd).toString
         case Right(p) => p.toString
       }
-      logger.message(s"$prefix$path0:$line$col" + (if (msgIt.hasNext) " " + msgIt.next() else ""))
+      logger.error(s"$prefix$path0:$line$col" + (if (msgIt.hasNext) " " + msgIt.next() else ""))
       for (line <- msgIt)
         logger.message(prefix + line)
       val codeOpt = {
@@ -199,15 +199,15 @@ object ConsoleBloopBuildClient {
         } yield line
       }
       for (code <- codeOpt)
-        code.linesIterator.map(prefix + _).foreach(logger.message(_))
+        code.linesIterator.map(prefix + _).foreach(logger.error(_))
       val canPrintUnderline = diag.getRange.getStart.getLine == diag.getRange.getEnd.getLine &&
         diag.getRange.getStart.getCharacter != null &&
         diag.getRange.getEnd.getCharacter != null &&
         codeOpt.nonEmpty
       if (canPrintUnderline) {
         val len =
           math.max(1, diag.getRange.getEnd.getCharacter - diag.getRange.getStart.getCharacter)
-        logger.message(
+        logger.error(
           prefix + " " * diag.getRange.getStart.getCharacter + "^" * len
         )
       }

modules/cli/src/main/scala/scala/cli/commands/shared/LoggingOptions.scala

@@ -13,7 +13,7 @@ final case class LoggingOptions(
   @Recurse
     verbosityOptions: VerbosityOptions = VerbosityOptions(),
   @Group("Logging")
-  @HelpMessage("Decrease verbosity")
+  @HelpMessage("Decrease logging verbosity")
   @Tag(tags.implementation)
   @Name("q")
     quiet: Boolean = false,

modules/cli/src/main/scala/scala/cli/internal/CliLogger.scala

@@ -37,8 +37,12 @@ class CliLogger(
     }
   }
 
-  def error(message: String) =
-    out.println(message)
+  def error(message: String) = {
+    System.err.println(verbosity)
+    if (verbosity >= -1)
+      out.println(message)
+  }
+
   def message(message: => String) =
     if (verbosity >= 0)
       out.println(message)
@@ -123,14 +127,20 @@ class CliLogger(
         printDiagnostic(ex.positions, Severity.Error, ex.getMessage(), contentCache, None)
     }
 
-  def log(ex: BuildException): Unit =
+  def log(ex: BuildException): Unit = {
+    System.err.println("Hello")
     if (verbosity >= 0)
       printEx(ex, new mutable.HashMap)
+  }
 
-  def debug(ex: BuildException): Unit =
+  def debug(ex: BuildException): Unit = {
+    System.err.println("Hello-debug")
     if (verbosity >= 2)
       printEx(ex, new mutable.HashMap)
-  def exit(ex: BuildException): Nothing =
+  }
+
+  def exit(ex: BuildException): Nothing = {
+    System.err.println("Hello-error")
     if (verbosity < 0)
       sys.exit(1)
     else if (verbosity == 0) {
@@ -139,6 +149,7 @@ class CliLogger(
     }
     else
       throw new Exception(ex)
+  }
 
   def coursierLogger(printBefore: String) =
     if (quiet)

modules/integration/src/test/scala/scala/cli/integration/LoggingTests.scala

@@ -0,0 +1,33 @@
+package scala.cli.integration
+
+import com.eed3si9n.expecty.Expecty.expect
+
+class LoggingTests extends ScalaCliSuite {
+  test("single -q should not suppresses compilation errors") {
+    TestInputs(
+      os.rel / "Hello.scala" ->
+        s"""object Hello extends App {
+           |  println("Hello"
+           |}
+           |""".stripMargin
+    ).fromRoot { root =>
+      val res = os.proc(TestUtil.cli, ".", "-q").call(cwd = root, check = false, mergeErrIntoOut = true)
+      val output = res.out.trim()
+      expect(output.contains("Hello.scala:3:1"))
+      expect(output.contains("error"))
+    }
+  }
+  test("single -q should not suppresses output from app") {
+    TestInputs(
+      os.rel / "Hello.scala" ->
+        s"""object Hello extends App {
+           |  println("Hello")
+           |}
+           |""".stripMargin
+    ).fromRoot { root =>
+      val res    = os.proc(TestUtil.cli, ".", "-q").call(cwd = root)
+      val output = res.out.trim()
+      expect(output.contains("Hello"))
+    }
+  }
+}

website/docs/commands/basics.md

@@ -368,3 +368,36 @@ Hello
 <!-- Expected:
 Hello
 -->
+
+### Logging
+
+To turn off logging in the application, pass the `-q` flag once. This will suppress all logging output except for errors:
+
+```scala title=Hello.scala
+object Hello extends App {
+  println("Hello"
+}
+```
+
+<ChainedSnippets>
+
+```bash fail
+scala-cli Hello.scala -q  
+```
+
+```text
+[error] ./Hello.scala:6:3: ')' expected, but '}' found
+[error]   }
+[error]   ^
+```
+
+<!-- Expected:
+[error] ./Hello.scala:6:3: ')' expected, but '}' found
+[error]   }
+[error]   ^
+-->
+
+</ChainedSnippets>
+
+Note that this will also suppress any logging related to tasks such as downloading dependencies, logs
+about the start of compilation, and so on.

website/docs/reference/cli-options.md

@@ -541,7 +541,7 @@ Available in commands:
 
 Aliases: `-q`
 
-Decrease verbosity
+Decrease logging verbosity
 
 ### `--progress`
 

website/docs/reference/scala-command/cli-options.md

@@ -568,7 +568,7 @@ Aliases: `-q`
 
 `IMPLEMENTATION specific` per Scala Runner specification
 
-Decrease verbosity
+Decrease logging verbosity
 
 ### `--progress`
 

website/docs/reference/scala-command/runner-specification.md

@@ -302,7 +302,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -827,7 +827,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -1354,7 +1354,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -1911,7 +1911,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -2490,7 +2490,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -3019,7 +3019,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -3614,7 +3614,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -3929,7 +3929,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -4206,7 +4206,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -4519,7 +4519,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -4598,7 +4598,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -4657,7 +4657,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -4748,7 +4748,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -5025,7 +5025,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -5350,7 +5350,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -5529,7 +5529,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`
 
@@ -5586,7 +5586,7 @@ Enable actionable diagnostics
 
 **--quiet**
 
-Decrease verbosity
+Decrease logging verbosity
 
 Aliases: `-q`