Clueless error message

[tribbloid]

Compiler version

3.3.6

Minimized code

N/A, bug triggered by bytecode

To reproduce, checkout https://github.com/tribbloid/dottyspike/blob/5099a9e880bc419ec92771a0dd317332e71834c9/ recursively and compile it

Output

[Error] : error while loading package,
  class file /home/peng/git/dottyspike/six-scala/module/spark/build/classes/scala/main/ai/acyclic/six/spark/package.class is broken (version 52.0),
  please check the JDK compatibility of your Scala version (3.3.6),
  reading aborted with class dotty.tools.tasty.UnpickleException:
  TASTy signature has wrong version.
 expected: {majorVersion: 28, minorVersion: 3}
 found   : {majorVersion: 28, minorVersion: 7}

This TASTy file was produced by a more recent, forwards incompatible release.
To read this TASTy file, please upgrade your tooling.
The TASTy file was produced by Scala 3.7.1.
one error found

Expectation

This error message revealed at least 2 problem:

1. The first part asked to "check the JDK compatibility", but the JDK of majorVersion 28 either doesn't exist or is out of production a long time ago. In my environment, the project is compiled using JDK 17 everywhere.

2. The second part reported that "The TASTy file was produced by Scala 3.7.1", but it is clearly suggested that the only compiler involved is Scala 3.3.6

The compiler should submit a consistency failure error automatically through telemetry in case it happened

[WojciechMazur]

The issue is mostly on how Exceptions in the compiler are wrapped:

1. In ClassfieParser we have catch RuntimeException, add our message and then show content of cause error:

   scala3/compiler/src/dotty/tools/dotc/core/classfile/ClassfileParser.scala

   Lines 307 to 313 in 9f5ca71

   	case e: RuntimeException =>
   	if (ctx.debug) e.printStackTrace()
   	val addendum = Header.Version.brokenVersionAddendum(classfileVersion)
   	throw new IOException(
   	i""" class file ${classfile.canonicalPath} is broken$addendum,
   	| reading aborted with ${e.getClass}:
   	| ${Option(e.getMessage).getOrElse("")}""")

2. The error related to TASTy version, the actual cause is actually emitted somewhere in TastyHeaderUnpickler

   scala3/tasty/src/dotty/tools/tasty/TastyHeaderUnpickler.scala

   Lines 178 to 185 in 90b068f

   	private def signatureString(
   	fileVersion: TastyVersion, toolVersion: TastyVersion, what: String, tool: Option[String]) = {
   	val optProducedBy = tool.fold("")(t => s", produced by $t")
   	s"""$what incompatible TASTy file has version ${fileVersion.show}$optProducedBy,
   	| expected ${toolVersion.validRange}.
   	|""".stripMargin
   	}

We should check here for actual cause, the first error message should be present only if it's not TASTy related

[tribbloid]

@WojciechMazur I agree, this may primarily be an error caused by gradle Scala plugin (gradle/gradle#35430)

but the error message can be more precise