compilation error with JVM 20

[yanns]

steps

By updating the JVM from 19 to OpenJDK20U-jre_x64_linux_hotspot_20.0.1_9 with scala 2.13.11 and sbt 1.9.0

problem

we have a new compilation error:

[error] scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
[error] scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:24)
[error] scala.reflect.internal.Mirrors$RootsBase.$anonfun$getModuleOrClass$6(Mirrors.scala:63)
[error] scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:63)
[error] scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:55)
[error] scala.reflect.internal.Mirrors$RootsBase.getRequiredClass(Mirrors.scala:55)
[error] scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass$lzycompute(Definitions.scala:293)
[error] scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass(Definitions.scala:293)
[error] scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1654)
[error] scala.tools.nsc.Global$Run.<init>(Global.scala:1249)
[error] xsbt.ZincCompiler$ZincRun.<init>(CallbackGlobal.scala:80)
[error] xsbt.CachedCompiler0.run(CompilerBridge.scala:161)
[error] xsbt.CachedCompiler0.run(CompilerBridge.scala:134)
[error] xsbt.CompilerBridge.run(CompilerBridge.scala:39)
[error] sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:91)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$7(MixedAnalyzingCompiler.scala:193)
[error] scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
[error] sbt.internal.inc.MixedAnalyzingCompiler.timed(MixedAnalyzingCompiler.scala:248)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4(MixedAnalyzingCompiler.scala:183)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4$adapted(MixedAnalyzingCompiler.scala:163)
[error] sbt.internal.inc.JarUtils$.withPreviousJar(JarUtils.scala:239)
[error] sbt.internal.inc.MixedAnalyzingCompiler.compileScala$1(MixedAnalyzingCompiler.scala:163)
[error] sbt.internal.inc.MixedAnalyzingCompiler.compile(MixedAnalyzingCompiler.scala:211)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1(IncrementalCompilerImpl.scala:534)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1$adapted(IncrementalCompilerImpl.scala:534)
[error] sbt.internal.inc.Incremental$.$anonfun$apply$5(Incremental.scala:179)
[error] sbt.internal.inc.Incremental$.$anonfun$apply$5$adapted(Incremental.scala:177)
[error] sbt.internal.inc.Incremental$$anon$2.run(Incremental.scala:463)
[error] sbt.internal.inc.IncrementalCommon$CycleState.next(IncrementalCommon.scala:116)
[error] sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:56)
[error] sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:52)
[error] sbt.internal.inc.IncrementalCommon.cycle(IncrementalCommon.scala:263

[adpi2]

I was not able to reproduce the issue:

$ eval $(cs java --jvm adoptium:1.20.0.1 --env)
$ sbt                                          
[info] welcome to sbt 1.9.0 (Eclipse Adoptium Java 20.0.1)
[info] loading global plugins from /home/piquerez/.sbt/1.0/plugins
[info] loading project definition from /home/piquerez/github/sbt/sbt-1204/project
[info] loading settings for project sbt-1204 from build.sbt ...
[info] set current project to sbt-1204 (in build file:/home/piquerez/github/sbt/sbt-1204/)
[info] sbt server started at local:///home/piquerez/.sbt/1.0/server/f27c1efd1ebeb2b494be/sock
[info] started sbt server
sbt:sbt-1204> compile
[info] compiling 1 Scala source to /home/piquerez/github/sbt/sbt-1204/target/scala-2.13/classes ...
[success] Total time: 2 s, completed Jun 16, 2023, 11:45:11 AM

I tried switching from adoptium:1.19.0.2 to adoptium:1.20.0.1 in some of my complex build and it worked fine.

@yanns do you have some more precise reproduction instructions (repo, OS, steps)?

[yanns]

It's an internal application. OS:

System information:
 Server Version: 20.10.18
 Storage Driver: overlay2
  Backing Filesystem: xfs
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Kernel Version: 5.15.0-1030-aws
 Operating System: Ubuntu 20.04.5 LTS
 OSType: linux
 Architecture: x86_64

JVM installed with jabba:

jabba install "20.0-custom=tgz+https://github.com/adoptium/temurin20-binaries/releases/download/jdk-20.0.1%2B9/OpenJDK20U-jre_x64_linux_hotspot_20.0.1_9.tar.gz"

I found the issue. There was the following option in build.sbt:

ThisBuild / scalacOptions ++= Seq("-release", "11")

Using the following produces the same issue:

ThisBuild / scalacOptions ++= Seq("-release", "12")

[yanns]

I'll try with other release values later.

[yanns]

when looking at https://docs.scala-lang.org/overviews/compiler-options/index.html, the flag release does not seem to support JVM 20:

-release RELEASE or --release RELEASE Compile for a specific version of the Java platform. Supported targets: 6, 7, 8, 9

The documentation might be outdated as I can use the values 11 and 12. Do you maybe know which values are possible?

[adpi2]

I found the issue. There was the following option in build.sbt:

ThisBuild / scalacOptions ++= Seq("-release", "11")

I still cannot reproduce the issue though.

Could it be an issue in the compiler itself? Can you try running coursier launch scalac:2.13.11 -- HelloWorld.scala -release 12?

Do you maybe know which values are possible?

According to this line it supports all versions from 8 to 21.

[vasilmkd]

This error looks similar to the error when the old Scala compilers are executed with newer JDK versions (9+) that do not have a proper rt.jar.

Sbt has solved this by running their bespoke java9-rt-export.jar (https://github.com/sbt/java9-rt-export) and then providing the output path via -Dscala.ext.dirs.