Internal compiler error in Scala 2.9.2 related to specialization

[Piotr Kołaczkowski]

Hi,

I'm getting the following exception when trying to specialize a trait in my project:

scala.tools.nsc.symtab.Types$TypeError: type mismatch;

 found   : Seq[com.viungo.simulator.expr.Expr[T]]

 required: Seq[com.viungo.simulator.expr.Expr[Double]]

at scala.tools.nsc.typechecker.Contexts$Context.error(Contexts.scala:298)

at scala.tools.nsc.typechecker.Infer$Inferencer.error(Infer.scala:207)

at scala.tools.nsc.typechecker.Infer$Inferencer.typeError(Infer.scala:217)

at scala.tools.nsc.typechecker.Infer$Inferencer.typeErrorTree(Infer.scala:232)

at scala.tools.nsc.typechecker.Typers$Typer.adapt(Typers.scala:936)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4282)

at scala.tools.nsc.typechecker.Duplicators$BodyDuplicator.typed(Duplicators.scala:310)

at scala.tools.nsc.typechecker.Typers$Typer.typedArg(Typers.scala:2191)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedArgs$3.apply(Typers.scala:2204)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedArgs$3.apply(Typers.scala:2203)

at scala.Tuple3$Zipped$$anonfun$map$1.apply(Tuple3.scala:66)

at scala.Tuple3$Zipped$$anonfun$map$1.apply(Tuple3.scala:64)

at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)

at scala.collection.immutable.List.foreach(List.scala:76)

at scala.Tuple3$Zipped.map(Tuple3.scala:64)

at scala.tools.nsc.typechecker.Typers$Typer.typedArgs(Typers.scala:2203)

at scala.tools.nsc.typechecker.Typers$Typer.doTypedApply(Typers.scala:2423)

at scala.tools.nsc.typechecker.Typers$Typer.typedApply$1(Typers.scala:3373)

at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:4106)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4273)

at scala.tools.nsc.typechecker.Duplicators$BodyDuplicator.typed(Duplicators.scala:310)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4333)

at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:3968)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4273)

at scala.tools.nsc.typechecker.Duplicators$BodyDuplicator.typed(Duplicators.scala:310)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedPattern$1.apply(Typers.scala:4371)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedPattern$1.apply(Typers.scala:4371)

at scala.tools.nsc.typechecker.Contexts$Context.withImplicitsDisabled(Contexts.scala:156)

at scala.tools.nsc.typechecker.Typers$Typer.typedPattern(Typers.scala:4371)

at scala.tools.nsc.typechecker.Typers$Typer.typedCase(Typers.scala:1941)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedCases$1.apply(Typers.scala:1975)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedCases$1.apply(Typers.scala:1974)

at scala.collection.immutable.List.loop$1(List.scala:148)

at scala.collection.immutable.List.mapConserve(List.scala:164)

at scala.tools.nsc.typechecker.Typers$Typer.typedCases(Typers.scala:1974)

at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:4005)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4273)

at scala.tools.nsc.typechecker.Duplicators$BodyDuplicator.typed(Duplicators.scala:298)

at scala.tools.nsc.typechecker.Typers$Typer.transformedOrTyped(Typers.scala:4430)

at scala.tools.nsc.typechecker.Typers$Typer.typedDefDef(Typers.scala:1760)

at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:3921)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4273)

at scala.tools.nsc.typechecker.Duplicators$BodyDuplicator.typed(Duplicators.scala:229)

at scala.tools.nsc.typechecker.Typers$Typer.typedStat$1(Typers.scala:2100)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$24.apply(Typers.scala:2184)

at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$24.apply(Typers.scala:2184)

at scala.collection.immutable.List.loop$1(List.scala:148)

at scala.collection.immutable.List.mapConserve(List.scala:164)

at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:2184)

at scala.tools.nsc.typechecker.Typers$Typer.typedBlock(Typers.scala:1919)

at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:3953)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4273)

at scala.tools.nsc.typechecker.Duplicators$BodyDuplicator.typed(Duplicators.scala:217)

at scala.tools.nsc.typechecker.Typers$Typer.transformedOrTyped(Typers.scala:4430)

at scala.tools.nsc.typechecker.Typers$Typer.typedDefDef(Typers.scala:1760)

at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:3921)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4273)

at scala.tools.nsc.typechecker.Duplicators$BodyDuplicator.typed(Duplicators.scala:229)

at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4333)

at scala.tools.nsc.typechecker.Duplicators.retyped(Duplicators.scala:32)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6.duplicateBody(SpecializeTypes.scala:1492)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6.transform(SpecializeTypes.scala:1375)

at scala.tools.nsc.ast.Trees$Transformer$$anonfun$transformTrees$1.apply(Trees.scala:873)

at scala.tools.nsc.ast.Trees$Transformer$$anonfun$transformTrees$1.apply(Trees.scala:873)

at scala.collection.immutable.List.loop$1(List.scala:148)

at scala.collection.immutable.List.mapConserve(List.scala:164)

at scala.tools.nsc.ast.Trees$Transformer.transformTrees(Trees.scala:873)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6$$anonfun$transform$16.apply(SpecializeTypes.scala:1354)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6$$anonfun$transform$16.apply(SpecializeTypes.scala:1354)

at scala.tools.nsc.ast.Trees$Transformer.atOwner(Trees.scala:899)

at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:38)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6.transform(SpecializeTypes.scala:1354)

at scala.tools.nsc.ast.Trees$Transformer.transformTemplate(Trees.scala:875)

at scala.tools.nsc.ast.Trees$Transformer$$anonfun$transform$2.apply(Trees.scala:767)

at scala.tools.nsc.ast.Trees$Transformer$$anonfun$transform$2.apply(Trees.scala:766)

at scala.tools.nsc.ast.Trees$Transformer.atOwner(Trees.scala:899)

at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:38)

at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:31)

at scala.tools.nsc.ast.Trees$Transformer.transform(Trees.scala:765)

at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.transform(TypingTransformers.scala:53)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6.transform(SpecializeTypes.scala:1475)

at scala.tools.nsc.ast.Trees$Transformer$$anonfun$transformStats$1.apply(Trees.scala:891)

at scala.tools.nsc.ast.Trees$Transformer$$anonfun$transformStats$1.apply(Trees.scala:889)

at scala.collection.immutable.List.loop$1(List.scala:148)

at scala.collection.immutable.List.mapConserve(List.scala:164)

at scala.tools.nsc.ast.Trees$Transformer.transformStats(Trees.scala:889)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6$$anonfun$transform$15.apply(SpecializeTypes.scala:1341)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6$$anonfun$transform$15.apply(SpecializeTypes.scala:1339)

at scala.tools.nsc.ast.Trees$Transformer.atOwner(Trees.scala:899)

at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:38)

at scala.tools.nsc.transform.SpecializeTypes$$anon$6.transform(SpecializeTypes.scala:1339)

at scala.tools.nsc.transform.SpecializeTypes$SpecializationTransformer$$anonfun$transform$37.apply(SpecializeTypes.scala:1694)

at scala.tools.nsc.transform.SpecializeTypes$SpecializationTransformer$$anonfun$transform$37.apply(SpecializeTypes.scala:1694)

at scala.tools.nsc.symtab.SymbolTable.atPhase(SymbolTable.scala:95)

at scala.tools.nsc.transform.SpecializeTypes$SpecializationTransformer.transform(SpecializeTypes.scala:1694)

at scala.tools.nsc.ast.Trees$Transformer.transformUnit(Trees.scala:892)

at scala.tools.nsc.transform.Transform$Phase.apply(Transform.scala:30)

at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:329)

at scala.tools.nsc.Global$GlobalPhase$$anonfun$run$1.apply(Global.scala:297)

at scala.tools.nsc.Global$GlobalPhase$$anonfun$run$1.apply(Global.scala:297)

at scala.collection.Iterator$class.foreach(Iterator.scala:772)

at scala.collection.mutable.ListBuffer$$anon$1.foreach(ListBuffer.scala:318)

at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:297)

at scala.tools.nsc.Global$Run.compileSources(Global.scala:953)

at scala.tools.nsc.Global$Run.compile(Global.scala:1041)

at xsbt.CompilerInterface.run(CompilerInterface.scala:82)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:597)

at xsbt.AnalyzingCompiler.call(AnalyzingCompiler.scala:40)

at xsbt.AnalyzingCompiler.apply(AnalyzingCompiler.scala:18)

at sbt.Compile.processScala(Compile.scala:76)

at sbt.CompilerCore$$anonfun$1.apply(Compile.scala:27)

at sbt.CompilerCore$$anonfun$1.apply(Compile.scala:27)

at sbt.CompilerCore$$anonfun$process$1$1.apply(Compile.scala:22)

at sbt.CompilerCore$$anonfun$process$1$1.apply(Compile.scala:22)

at sbt.CompilerCore$$anonfun$doCompile$3.apply(Compile.scala:45)

at sbt.CompilerCore$$anonfun$doCompile$3.apply(Compile.scala:42)

at scala.Option.orElse(Option.scala:102)

at sbt.CompilerCore.doCompile(Compile.scala:41)

at sbt.CompilerCore.apply(Compile.scala:29)

at sbt.AbstractCompileConditional.run$1(Conditional.scala:341)

at sbt.AbstractCompileConditional$$anonfun$3.apply(Conditional.scala:344)

at sbt.AbstractCompileConditional$$anonfun$3.apply(Conditional.scala:344)

at sbt.classfile.Analyze$.apply(Analyze.scala:110)

at sbt.AbstractCompileConditional.execute(Conditional.scala:344)

at sbt.Conditional$class.run(Conditional.scala:43)

at sbt.AbstractCompileConditional.run(Conditional.scala:231)

at sbt.BasicScalaProject.sbt$BasicScalaProject$$doCompile(DefaultProject.scala:260)

at sbt.BasicScalaProject$$anonfun$compileAction$1.apply(DefaultProject.scala:274)

at sbt.BasicScalaProject$$anonfun$compileAction$1.apply(DefaultProject.scala:274)

at sbt.TaskManager$Task.invoke(TaskManager.scala:62)

at sbt.impl.RunTask.doRun$1(RunTask.scala:77)

at sbt.impl.RunTask.runTask(RunTask.scala:85)

at sbt.impl.RunTask.sbt$impl$RunTask$$runIfNotRoot(RunTask.scala:60)

at sbt.impl.RunTask$$anonfun$runTasksExceptRoot$2.apply(RunTask.scala:48)

at sbt.impl.RunTask$$anonfun$runTasksExceptRoot$2.apply(RunTask.scala:48)

at sbt.Distributor$Run$Worker$$anonfun$2.apply(ParallelRunner.scala:131)

at sbt.Distributor$Run$Worker$$anonfun$2.apply(ParallelRunner.scala:131)

at sbt.Control$.trapUnit(Control.scala:19)

at sbt.Distributor$Run$Worker.run(ParallelRunner.scala:131)

1. How can I debug which part of my code causes this? If the compiler at least could tell me which method is the problem, it would be easier to minimize and submit an error report. The code compiles fine without specialization.

2. Should I give a try to Scala 2.10 M3? Does it have some specialization fixes that have not been backported to 2.9 yet?

Thanks, 

Piotr

[Jason Zaugg]

On Sat, Jun 2, 2012 at 10:57 AM, Piotr Kołaczkowski <pkol...@gmail.com> wrote:
> I'm getting the following exception when trying to specialize a trait in my
> project:

[snip]

> 1. How can I debug which part of my code causes this? If the compiler at
> least could tell me which method is the problem, it would be easier to
> minimize and submit an error report. The code compiles fine without
> specialization.
> 2. Should I give a try to Scala 2.10 M3? Does it have some specialization
> fixes that have not been backported to 2.9 yet?

Try #2. You will get better diagnostics to tell you which code is triggering
the crash. It will be easier if you can first reproduce in a section of code
without third party dependencies, which might not be cross-compiled against
2.10.0-M3.

Otherwise, try: scalac -verbose -Ydebug -Ylog:all, and see what was reported
last in the reams of output.

-jason