Failed +test on a fresh checkout of 1.5.x

[ignasi35]

Clone the repo and checkout commit 915fddbb65719ead69ebc3b110d4b15394de54f0.

Run sbt +test.

Depending on the launch script vendor and version the command above will consistently fail or will fail once before it succeeds.

For example: using vanilla sbt freshly downloaded from https://www.scala-sbt.org/ the first execution of sbt +test fails but the second execution consistently succeeds.

[ignasi35]

cc @dwijnand we could use your fu

[SethTisue]

(Note that Dale is on break this week and next.)

When you say it fails, what happens?

[mkurz]

I can reproduce (and have a fix ;): It's a race condition.

It happens only when running the tests against Scala 2.10.7. I could reproduce everytime with Java 8 (openjdk version "1.8.0_282") and sometimes, but not always, with Java 11 (openjdk version "11.0.10" 2021-01-19). I have sbt 1.4.8 installed on my Ubuntu notebook.

I started with the ~/.sbt folder removed, but actually I think that is not even necessary, if you want to reproduce just make sure

• you use Java 8 to constantly run into the issue and
• everytime after shutting down sbt remove the target folder(s), e.g. I did: rm -rf target/ project/target/ (for a clean run next time you run sbt)

How to reproduce: git checkout 915fddbb65719ead69ebc3b110d4b15394de54f0

Then sbt -java-home /path/to/adoptopenjdk8/ ++2.10.7 test

Click here to see the errors (because it's a race condition, sometimes different errors occur)

``` [info] welcome to sbt 1.3.13 (AdoptOpenJDK Java 1.8.0_282) [info] loading global plugins from /home/mkurz/.sbt/1.0/plugins [info] loading settings for project twirl-build from plugins.sbt ... [info] loading project definition from /home/mkurz/work/twirl/project [warn] There may be incompatibilities among your library dependencies; run 'evicted' to see detailed eviction warnings. [info] loading settings for project twirl from build.sbt ... [info] set current project to twirl (in build file:/home/mkurz/work/twirl/) [info] Setting Scala version to 2.10.7 on 5 projects. [info] Excluded 1 projects, run ++ 2.10.7 -v for more details. [info] Reapplying settings... [info] set current project to twirl (in build file:/home/mkurz/work/twirl/) scala.reflect.runtime.ReflectError: value Predef is not a package at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$$makeScalaPackage(JavaMirrors.scala:915) at scala.reflect.runtime.JavaMirrors$class.missingHook(JavaMirrors.scala:1299) at scala.reflect.runtime.JavaUniverse.missingHook(JavaUniverse.scala:12) at scala.reflect.internal.Mirrors$RootsBase.universeMissingHook(Mirrors.scala:77) | => pat scala.reflect.internal.Mirrors$RootsBase.missingHook(Mirrors.scala:79) | => cat scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:226) | => aat scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) | => pat scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) | => aat scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:200) | => aat scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) at scala.reflect.internal.pickling.UnPickler$Scan.readType(UnPickler.scala:346) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readTypeRef(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.readTree(UnPickler.scala:511) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotArg(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotationInfo(UnPickler.scala:477) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolAnnotation(UnPickler.scala:491) at scala.reflect.internal.pickling.UnPickler$Scan.run(UnPickler.scala:88) at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:37) at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) at scala.reflect.internal.Types$Type.member(Types.scala:680) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) at org.scalatest.tools.Framework.runner(Framework.scala:987) at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) at scala.collection.immutable.Map$Map2.foreach(Map.scala:159) at scala.collection.TraversableLike.map(TraversableLike.scala:238) at scala.collection.TraversableLike.map$(TraversableLike.scala:231) at scala.collection.AbstractTraversable.map(Traversable.scala:108) at sbt.Defaults$.createTestRunners(Defaults.scala:1093) at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) at scala.Function1.$anonfun$compose$1(Function1.scala:49) at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) at sbt.std.Transform$$anon$4.work(Transform.scala:67) at sbt.Execute.$anonfun$submit$2(Execute.scala:281) at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) at sbt.Execute.work(Execute.scala:290) at sbt.Execute.$anonfun$submit$1(Execute.scala:281) at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) scala.reflect.runtime.ReflectError: value Predef is not a package at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$$makeScalaPackage(JavaMirrors.scala:915) at scala.reflect.runtime.JavaMirrors$class.missingHook(JavaMirrors.scala:1299) at scala.reflect.runtime.JavaUniverse.missingHook(JavaUniverse.scala:12) at scala.reflect.internal.Mirrors$RootsBase.universeMissingHook(Mirrors.scala:77) at scala.reflect.internal.Mirrors$RootsBase.missingHook(Mirrors.scala:79) at scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:226) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) at scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:200) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) at scala.reflect.internal.pickling.UnPickler$Scan.readType(UnPickler.scala:346) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readTypeRef(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.readTree(UnPickler.scala:511) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotArg(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotationInfo(UnPickler.scala:477) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolAnnotation(UnPickler.scala:491) at scala.reflect.internal.pickling.UnPickler$Scan.run(UnPickler.scala:88) at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:37) at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) at scala.reflect.internal.Types$Type.member(Types.scala:680) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) at org.scalatest.tools.Framework.runner(Framework.scala:987) at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) at scala.collection.immutable.Map$Map2.foreach(Map.scala:159) at scala.collection.TraversableLike.map(TraversableLike.scala:238) at scala.collection.TraversableLike.map$(TraversableLike.scala:231) at scala.collection.AbstractTraversable.map(Traversable.scala:108) at sbt.Defaults$.createTestRunners(Defaults.scala:1093) at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) at scala.Function1.$anonfun$compose$1(Function1.scala:49) at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) at sbt.std.Transform$$anon$4.work(Transform.scala:67) at sbt.Execute.$anonfun$submit$2(Execute.scala:281) at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) at sbt.Execute.work(Execute.scala:290) at sbt.Execute.$anonfun$submit$1(Execute.scala:281) at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) scala.reflect.runtime.ReflectError: value Predef is not a package at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$$makeScalaPackage(JavaMirrors.scala:915) at scala.reflect.runtime.JavaMirrors$class.missingHook(JavaMirrors.scala:1299) at scala.reflect.runtime.JavaUniverse.missingHook(JavaUniverse.scala:12) at scala.reflect.internal.Mirrors$RootsBase.universeMissingHook(Mirrors.scala:77) at scala.reflect.internal.Mirrors$RootsBase.missingHook(Mirrors.scala:79) at scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:226) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) at scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:200) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) at scala.reflect.internal.pickling.UnPickler$Scan.readType(UnPickler.scala:346) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readTypeRef(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.readTree(UnPickler.scala:511) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotArg(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotationInfo(UnPickler.scala:477) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolAnnotation(UnPickler.scala:491) at scala.reflect.internal.pickling.UnPickler$Scan.run(UnPickler.scala:88) at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:37) at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) at scala.reflect.internal.Types$Type.member(Types.scala:680) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) at org.scalatest.tools.Framework.runner(Framework.scala:987) at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) at scala.collection.immutable.Map$Map1.foreach(Map.scala:128) at scala.collection.TraversableLike.map(TraversableLike.scala:238) at scala.collection.TraversableLike.map$(TraversableLike.scala:231) at scala.collection.AbstractTraversable.map(Traversable.scala:108) at sbt.Defaults$.createTestRunners(Defaults.scala:1093) at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) at scala.Function1.$anonfun$compose$1(Function1.scala:49) at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) at sbt.std.Transform$$anon$4.work(Transform.scala:67) at sbt.Execute.$anonfun$submit$2(Execute.scala:281) at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) at sbt.Execute.work(Execute.scala:290) at sbt.Execute.$anonfun$submit$1(Execute.scala:281) at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) scala.reflect.runtime.ReflectError: value Predef is not a package at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$$makeScalaPackage(JavaMirrors.scala:915) at scala.reflect.runtime.JavaMirrors$class.missingHook(JavaMirrors.scala:1299) at scala.reflect.runtime.JavaUniverse.missingHook(JavaUniverse.scala:12) at scala.reflect.internal.Mirrors$RootsBase.universeMissingHook(Mirrors.scala:77) at scala.reflect.internal.Mirrors$RootsBase.missingHook(Mirrors.scala:79) at scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:226) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) at scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:200) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:250) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:783) at scala.reflect.internal.pickling.UnPickler$Scan.readType(UnPickler.scala:346) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readTypeRef(UnPickler.scala:792) at scala.reflect.internal.pickling.UnPickler$Scan.readTree(UnPickler.scala:511) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readAnnotArg$1.apply(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:171) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotArg(UnPickler.scala:443) at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotationInfo(UnPickler.scala:477) at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolAnnotation(UnPickler.scala:491) at scala.reflect.internal.pickling.UnPickler$Scan.run(UnPickler.scala:88) at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:37) at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) at scala.reflect.internal.Types$Type.member(Types.scala:680) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) at org.scalatest.tools.Framework.runner(Framework.scala:987) at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) at scala.collection.immutable.Map$Map1.foreach(Map.scala:128) at scala.collection.TraversableLike.map(TraversableLike.scala:238) at scala.collection.TraversableLike.map$(TraversableLike.scala:231) at scala.collection.AbstractTraversable.map(Traversable.scala:108) at sbt.Defaults$.createTestRunners(Defaults.scala:1093) at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) at scala.Function1.$anonfun$compose$1(Function1.scala:49) at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) at sbt.std.Transform$$anon$4.work(Transform.scala:67) at sbt.Execute.$anonfun$submit$2(Execute.scala:281) at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) at sbt.Execute.work(Execute.scala:290) at sbt.Execute.$anonfun$submit$1(Execute.scala:281) at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) [info] BufferedContentSpec: [info] equality checking [info] - should return false for BufferedContents with the same body but different implementations [info] - should return false for BufferedContents with different bodies but the same implementations [info] - should return true for BufferedContents with the same body and the same implementation [info] StringInterpolationSpec: [info] StringInterpolation [info] - should leave string parts untouched [info] - should escape interpolated arguments [info] - should leave nested templates untouched [info] - should display arguments as they would be displayed in a template [info] FormatSpec: [info] Formats [info] - should show null text values as empty [info] HtmlFormat [info] - should escape '<', '&' and '>' [info] - should escape single quotes [info] - should escape double quotes [info] - should not escape non-ASCII characters [info] JavaScriptFormat [info] - should escape ''', '"' and '\' [info] Run completed in 457 milliseconds. [info] Total number of tests run: 13 [info] Suites: completed 3, aborted 0 [info] Tests: succeeded 13, failed 0, canceled 0, ignored 0, pending 0 [info] All tests passed. [error] java.lang.RuntimeException: error reading Scala signature of org.scalatest.package: value Predef is not a package [error] at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:45) [error] at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) [error] at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) [error] at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) [error] at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) [error] at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) [error] at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) [error] at scala.reflect.internal.Types$Type.member(Types.scala:680) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) [error] at org.scalatest.tools.Framework.runner(Framework.scala:987) [error] at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) [error] at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) [error] at scala.collection.immutable.Map$Map2.foreach(Map.scala:159) [error] at scala.collection.TraversableLike.map(TraversableLike.scala:238) [error] at scala.collection.TraversableLike.map$(TraversableLike.scala:231) [error] at scala.collection.AbstractTraversable.map(Traversable.scala:108) [error] at sbt.Defaults$.createTestRunners(Defaults.scala:1093) [error] at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) [error] at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) [error] at scala.Function1.$anonfun$compose$1(Function1.scala:49) [error] at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) [error] at sbt.std.Transform$$anon$4.work(Transform.scala:67) [error] at sbt.Execute.$anonfun$submit$2(Execute.scala:281) [error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) [error] at sbt.Execute.work(Execute.scala:290) [error] at sbt.Execute.$anonfun$submit$1(Execute.scala:281) [error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) [error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [error] at java.lang.Thread.run(Thread.java:748) [error] java.lang.RuntimeException: error reading Scala signature of org.scalatest.package: value Predef is not a package [error] at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:45) [error] at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) [error] at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) [error] at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) [error] at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) [error] at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) [error] at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) [error] at scala.reflect.internal.Types$Type.member(Types.scala:680) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) [error] at org.scalatest.tools.Framework.runner(Framework.scala:987) [error] at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) [error] at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) [error] at scala.collection.immutable.Map$Map2.foreach(Map.scala:159) [error] at scala.collection.TraversableLike.map(TraversableLike.scala:238) [error] at scala.collection.TraversableLike.map$(TraversableLike.scala:231) [error] at scala.collection.AbstractTraversable.map(Traversable.scala:108) [error] at sbt.Defaults$.createTestRunners(Defaults.scala:1093) [error] at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) [error] at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) [error] at scala.Function1.$anonfun$compose$1(Function1.scala:49) [error] at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) [error] at sbt.std.Transform$$anon$4.work(Transform.scala:67) [error] at sbt.Execute.$anonfun$submit$2(Execute.scala:281) [error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) [error] at sbt.Execute.work(Execute.scala:290) [error] at sbt.Execute.$anonfun$submit$1(Execute.scala:281) [error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) [error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [error] at java.lang.Thread.run(Thread.java:748) [error] java.lang.RuntimeException: error reading Scala signature of org.scalatest.package: value Predef is not a package [error] at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:45) [error] at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) [error] at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) [error] at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) [error] at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) [error] at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) [error] at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) [error] at scala.reflect.internal.Types$Type.member(Types.scala:680) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) [error] at org.scalatest.tools.Framework.runner(Framework.scala:987) [error] at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) [error] at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) [error] at scala.collection.immutable.Map$Map1.foreach(Map.scala:128) [error] at scala.collection.TraversableLike.map(TraversableLike.scala:238) [error] at scala.collection.TraversableLike.map$(TraversableLike.scala:231) [error] at scala.collection.AbstractTraversable.map(Traversable.scala:108) [error] at sbt.Defaults$.createTestRunners(Defaults.scala:1093) [error] at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) [error] at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) [error] at scala.Function1.$anonfun$compose$1(Function1.scala:49) [error] at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) [error] at sbt.std.Transform$$anon$4.work(Transform.scala:67) [error] at sbt.Execute.$anonfun$submit$2(Execute.scala:281) [error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) [error] at sbt.Execute.work(Execute.scala:290) [error] at sbt.Execute.$anonfun$submit$1(Execute.scala:281) [error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) [error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [error] at java.lang.Thread.run(Thread.java:748) [error] java.lang.RuntimeException: error reading Scala signature of org.scalatest.package: value Predef is not a package [error] at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:45) [error] at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:565) [error] at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:32) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:244) [error] at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:300) [error] at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:89) [error] at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1231) [error] at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2407) [error] at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2412) [error] at scala.reflect.internal.Types$Type.findMember(Types.scala:1173) [error] at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:722) [error] at scala.reflect.internal.Types$Type.member(Types.scala:680) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:43) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40) [error] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:72) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161) [error] at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:21) [error] at org.scalatest.tools.Framework.runner(Framework.scala:987) [error] at sbt.Defaults$.$anonfun$createTestRunners$1(Defaults.scala:1099) [error] at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) [error] at scala.collection.immutable.Map$Map1.foreach(Map.scala:128) [error] at scala.collection.TraversableLike.map(TraversableLike.scala:238) [error] at scala.collection.TraversableLike.map$(TraversableLike.scala:231) [error] at scala.collection.AbstractTraversable.map(Traversable.scala:108) [error] at sbt.Defaults$.createTestRunners(Defaults.scala:1093) [error] at sbt.Defaults$.allTestGroupsTask(Defaults.scala:1161) [error] at sbt.Defaults$.$anonfun$testTasks$10(Defaults.scala:898) [error] at scala.Function1.$anonfun$compose$1(Function1.scala:49) [error] at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62) [error] at sbt.std.Transform$$anon$4.work(Transform.scala:67) [error] at sbt.Execute.$anonfun$submit$2(Execute.scala:281) [error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19) [error] at sbt.Execute.work(Execute.scala:290) [error] at sbt.Execute.$anonfun$submit$1(Execute.scala:281) [error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178) [error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [error] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [error] at java.lang.Thread.run(Thread.java:748) [error] (parser / Test / executeTests) error reading Scala signature of org.scalatest.package: value Predef is not a package [error] (compiler / Test / executeTests) error reading Scala signature of org.scalatest.package: value Predef is not a package [error] (plugin / Test / executeTests) error reading Scala signature of org.scalatest.package: value Predef is not a package [error] (apiJVM / Test / executeTests) error reading Scala signature of org.scalatest.package: value Predef is not a package [error] Total time: 4 s, completed Mar 17, 2021 10:57:01 PM ```

As a workaround we can restrict the total number of concurrently runnings tasks to 1, see #405 I can confirm with my patch the errors are gone.

Googling a bit I found other have/had the problem as well

• https://github.com/scala/bug/issues/6240 (I think that is the issue we are running into which got fixed in Scala 2.11.0-M7)
• https://groups.google.com/g/scala-user/c/ngraWYYZ0h0
• https://github.com/scala/pickling/issues/369
• https://groups.google.com/g/scala-user/c/ywacXjVYDYY

[SethTisue]

Scala 2.10 😱

[ignasi35]

When you say it fails, what happens?

Apologies for the poor reporting. I was in a hurry on my way out the door. 😅 I see @mkurz explained it in detail and provided a fix.

[mkurz]

I think we are OK to close this now.