How do I show the stack trace when the compiler crashes #2464

bishabosha · 2023-10-16T10:00:35Z

bishabosha
Oct 16, 2023

If I compile code that crashes the compiler, how do I print the stack trace,

e.g. this crashes:

//> using scala 3.3.1

trait Lam:
  type F[_]
  extension [A, B](f: F[A => B]) def apply(arg: F[A]): F[B]
  def lam[A, B](f: F[A] => F[B]): F[A => B]
  final def id[A]: F[A => A] = lam(identity[F[A]])

object LamInterpreter extends Lam:
  type F[t] = t
  def lam[A, B](f: F[A] => F[B]): F[A => B] = f
  extension [A, B](f: F[A => B]) def apply(arg: F[A]): F[B] = f(arg)


class Church[A](using val l: Lam):
  import l.*
  type Nat = F[(A => A) => (A => A)]
  def zero: Nat = id
  extension (n: Nat) def suc: Nat = lam(f => lam(x => f(n(f)(x))))

given [A](using l: Lam): Church[A] = Church()


@main
def churchTest = 
  given Lam = LamInterpreter
  val c: Church[Int] = summon
  summon[c.Nat =:= ((Int => Int) => (Int => Int))]

but I will only see the base error message, it seems stack traces are scrubbed?

Compiling project (Scala 3.3.1, JVM)
exception occurred while typechecking /var/folders/m4/4dsrk6zn74v3zzpk34nj11mh0000gn/T/10267835206784810512/.scala-build/10267835206784810512_fc963bf85b-67a27a2e40/src_generated/main/stdin.scala

  exception occurred while compiling List(/var/folders/m4/4dsrk6zn74v3zzpk34nj11mh0000gn/T/10267835206784810512/.scala-build/10267835206784810512_fc963bf85b-67a27a2e40/src_generated/main/stdin.scala)

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/lampepfl/dotty/issues/new/choose

     while compiling: <no file>
        during phase: <no phase>
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.10
    compiler version: version 3.3.1
            settings: -bootclasspath /Users/jamie/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala3-library_3/3.3.1/scala3-library_3-3.3.1.jar:/Users/jamie/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar -classpath /private/var/folders/m4/4dsrk6zn74v3zzpk34nj11mh0000gn/T/10267835206784810512/.scala-build/.bloop/10267835206784810512_fc963bf85b-67a27a2e40/bloop-internal-classes/main-CFNsXIs-QoKgSk69n_mYYg==:/var/folders/m4/4dsrk6zn74v3zzpk34nj11mh0000gn/T/10267835206784810512/.scala-build/10267835206784810512_fc963bf85b-67a27a2e40/classes/classes-empty-10267835206784810512_fc963bf85b-67a27a2e40 -d /private/var/folders/m4/4dsrk6zn74v3zzpk34nj11mh0000gn/T/10267835206784810512/.scala-build/.bloop/10267835206784810512_fc963bf85b-67a27a2e40/bloop-internal-classes/main-CFNsXIs-QoKgSk69n_mYYg== -java-output-version 21 -sourceroot /var/folders/m4/4dsrk6zn74v3zzpk34nj11mh0000gn/T/10267835206784810512

                tree: EmptyTree
       tree position: :<unknown>
           tree type: <notype>
              symbol: val <none>
           call site: package <root> in module class <root>

  == Source file context for tree position ==


Error compiling project (Scala 3.3.1, JVM)
Error: Unexpected error when compiling 10267835206784810512_fc963bf85b-67a27a2e40: 'assertion failed'
Compilation failed

Gedochao · 2023-10-17T07:20:27Z

Gedochao
Oct 17, 2023
Maintainer

It seems the stacktrace gets eaten by Bloop.
An easy workaround to get the stacktrace is to not use Bloop for this. (pass --server=false)

▶ scala-cli crash.scala --server=false
java.lang.AssertionError: assertion failed while typechecking /Users/pchabelski/IdeaProjects/scala-cli-tests/compiler-crash/crash.scala
exception occurred while typechecking /Users/pchabelski/IdeaProjects/scala-cli-tests/compiler-crash/crash.scala

  exception occurred while compiling List(/Users/pchabelski/IdeaProjects/scala-cli-tests/compiler-crash/crash.scala)

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/lampepfl/dotty/issues/new/choose

     while compiling: <no file>
        during phase: <no phase>
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.10
    compiler version: version 3.3.1
            settings: -classpath /Users/pchabelski/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala3-library_3/3.3.1/scala3-library_3-3.3.1.jar:/Users/pchabelski/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar -d /Users/pchabelski/IdeaProjects/scala-cli-tests/compiler-crash/.scala-build/compiler-crash_a69ec373e9-fd842dd7b2/classes/main -java-output-version 17 -sourceroot /Users/pchabelski/IdeaProjects/scala-cli-tests/compiler-crash

                tree: EmptyTree
       tree position: :<unknown>
           tree type: <notype>
              symbol: val <none>
           call site: package <root> in module class <root>

  == Source file context for tree position ==


Exception in thread "main" java.lang.AssertionError: assertion failed
        at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:11)
        at dotty.tools.dotc.ast.tpd$.TypeApply(tpd.scala:60)
        at dotty.tools.dotc.ast.tpd$TreeOps$.appliedToTypeTrees$extension(tpd.scala:985)
        at dotty.tools.dotc.typer.Typer.adapt1(Typer.scala:4255)
        at dotty.tools.dotc.typer.Typer.adapt(Typer.scala:3587)
        at dotty.tools.dotc.typer.ProtoTypes$FunProto.typedArg(ProtoTypes.scala:497)
        at dotty.tools.dotc.typer.Applications$ApplyToUntyped.typedArg(Applications.scala:897)
        at dotty.tools.dotc.typer.Applications$ApplyToUntyped.typedArg(Applications.scala:897)
        at dotty.tools.dotc.typer.Applications$Application.addTyped$1(Applications.scala:589)
        at dotty.tools.dotc.typer.Applications$Application.matchArgs(Applications.scala:653)
        at dotty.tools.dotc.typer.Applications$Application.init(Applications.scala:492)
        at dotty.tools.dotc.typer.Applications$TypedApply.<init>(Applications.scala:779)
        at dotty.tools.dotc.typer.Applications$ApplyToUntyped.<init>(Applications.scala:896)
        at dotty.tools.dotc.typer.Applications.ApplyTo(Applications.scala:1126)
        at dotty.tools.dotc.typer.Applications.ApplyTo$(Applications.scala:352)
        at dotty.tools.dotc.typer.Typer.ApplyTo(Typer.scala:116)
        at dotty.tools.dotc.typer.Applications.simpleApply$1(Applications.scala:969)
        at dotty.tools.dotc.typer.Applications.realApply$1$$anonfun$2(Applications.scala:1052)
        at dotty.tools.dotc.typer.Typer.tryEither(Typer.scala:3324)
        at dotty.tools.dotc.typer.Applications.realApply$1(Applications.scala:1063)
        at dotty.tools.dotc.typer.Applications.typedApply(Applications.scala:1101)
        at dotty.tools.dotc.typer.Applications.typedApply$(Applications.scala:352)
        at dotty.tools.dotc.typer.Typer.typedApply(Typer.scala:116)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3048)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3112)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3184)
        at dotty.tools.dotc.typer.Implicits.tryConversion$1(Implicits.scala:1136)
        at dotty.tools.dotc.typer.Implicits.typedImplicit(Implicits.scala:1167)
        at dotty.tools.dotc.typer.Implicits.typedImplicit$(Implicits.scala:818)
        at dotty.tools.dotc.typer.Typer.typedImplicit(Typer.scala:116)
        at dotty.tools.dotc.typer.Implicits$ImplicitSearch.tryImplicit(Implicits.scala:1242)
        at dotty.tools.dotc.typer.Implicits$ImplicitSearch.rank$1(Implicits.scala:1341)
        at dotty.tools.dotc.typer.Implicits$ImplicitSearch.searchImplicit(Implicits.scala:1511)
        at dotty.tools.dotc.typer.Implicits$ImplicitSearch.searchImplicit(Implicits.scala:1539)
        at dotty.tools.dotc.typer.Implicits$ImplicitSearch.searchImplicit(Implicits.scala:1547)
        at dotty.tools.dotc.typer.Implicits$ImplicitSearch.bestImplicit(Implicits.scala:1572)
        at dotty.tools.dotc.typer.Implicits.inferImplicit(Implicits.scala:1060)
        at dotty.tools.dotc.typer.Implicits.inferImplicit$(Implicits.scala:818)
        at dotty.tools.dotc.typer.Typer.inferImplicit(Typer.scala:116)
        at dotty.tools.dotc.typer.Implicits.inferView(Implicits.scala:856)
        at dotty.tools.dotc.typer.Implicits.inferView$(Implicits.scala:818)
        at dotty.tools.dotc.typer.Typer.inferView(Typer.scala:116)
        at dotty.tools.dotc.typer.Implicits.viewExists(Implicits.scala:831)
        at dotty.tools.dotc.typer.Implicits.viewExists$(Implicits.scala:818)
        at dotty.tools.dotc.typer.Typer.viewExists(Typer.scala:116)
        at dotty.tools.dotc.typer.Implicits.ignoredConvertibleImplicits$1$$anonfun$3(Implicits.scala:960)
        at scala.collection.Iterator$$anon$6.hasNext(Iterator.scala:479)
        at scala.collection.Iterator.isEmpty(Iterator.scala:466)
        at scala.collection.Iterator.isEmpty$(Iterator.scala:466)
        at scala.collection.AbstractIterator.isEmpty(Iterator.scala:1300)
        at scala.collection.View$Filter.isEmpty(View.scala:146)
        at scala.collection.IterableOnceOps.nonEmpty(IterableOnce.scala:833)
        at scala.collection.IterableOnceOps.nonEmpty$(IterableOnce.scala:833)
        at scala.collection.AbstractIterable.nonEmpty(Iterable.scala:933)
        at dotty.tools.dotc.reporting.MissingImplicitArgument.noChainConversionsNote$1(messages.scala:2838)
        at dotty.tools.dotc.reporting.MissingImplicitArgument.msgPostscript$$anonfun$4(messages.scala:2846)
        at scala.Option.orElse(Option.scala:477)
        at dotty.tools.dotc.reporting.MissingImplicitArgument.msgPostscript(messages.scala:2846)
        at dotty.tools.dotc.reporting.Message.message$$anonfun$1(Message.scala:345)
        at dotty.tools.dotc.reporting.Message.inMessageContext(Message.scala:341)
        at dotty.tools.dotc.reporting.Message.message(Message.scala:345)
        at dotty.tools.dotc.reporting.Message.isNonSensical(Message.scala:322)
        at dotty.tools.dotc.reporting.HideNonSensicalMessages.isHidden(HideNonSensicalMessages.scala:16)
        at dotty.tools.dotc.reporting.HideNonSensicalMessages.isHidden$(HideNonSensicalMessages.scala:10)
        at dotty.tools.dotc.reporting.AbstractReporter.isHidden(AbstractReporter.scala:8)
        at dotty.tools.dotc.reporting.Reporter.issueUnconfigured(Reporter.scala:156)
        at dotty.tools.dotc.reporting.Reporter.go$1(Reporter.scala:181)
        at dotty.tools.dotc.reporting.Reporter.issueIfNotSuppressed(Reporter.scala:200)
        at dotty.tools.dotc.reporting.Reporter.report(Reporter.scala:203)
        at dotty.tools.dotc.report$.error(report.scala:68)
        at dotty.tools.dotc.typer.Typer.issueErrors$1$$anonfun$1(Typer.scala:3808)
        at scala.runtime.function.JProcedure3.apply(JProcedure3.java:15)
        at scala.runtime.function.JProcedure3.apply(JProcedure3.java:10)
        at scala.collection.LazyZip3.foreach(LazyZipOps.scala:248)
        at dotty.tools.dotc.typer.Typer.issueErrors$1(Typer.scala:3810)
        at dotty.tools.dotc.typer.Typer.addImplicitArgs$1(Typer.scala:3832)
        at dotty.tools.dotc.typer.Typer.adaptNoArgsImplicitMethod$1(Typer.scala:3849)
        at dotty.tools.dotc.typer.Typer.adaptNoArgs$1(Typer.scala:4038)
        at dotty.tools.dotc.typer.Typer.adapt1(Typer.scala:4268)
        at dotty.tools.dotc.typer.Typer.adapt(Typer.scala:3587)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3184)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3188)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3300)
        at dotty.tools.dotc.typer.Typer.typedBlock(Typer.scala:1166)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3056)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3112)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3184)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3188)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3300)
        at dotty.tools.dotc.typer.Namer.typedAheadExpr$$anonfun$1(Namer.scala:1653)
        at dotty.tools.dotc.typer.Namer.typedAhead(Namer.scala:1643)
        at dotty.tools.dotc.typer.Namer.typedAheadExpr(Namer.scala:1653)
        at dotty.tools.dotc.typer.Namer.typedAheadRhs$1$$anonfun$1(Namer.scala:1906)
        at dotty.tools.dotc.inlines.PrepareInlineable$.dropInlineIfError(PrepareInlineable.scala:243)
        at dotty.tools.dotc.typer.Namer.typedAheadRhs$1(Namer.scala:1906)
        at dotty.tools.dotc.typer.Namer.rhsType$1(Namer.scala:1914)
        at dotty.tools.dotc.typer.Namer.cookedRhsType$1(Namer.scala:1932)
        at dotty.tools.dotc.typer.Namer.lhsType$1(Namer.scala:1933)
        at dotty.tools.dotc.typer.Namer.inferredResultType(Namer.scala:1944)
        at dotty.tools.dotc.typer.Namer.inferredType$1(Namer.scala:1691)
        at dotty.tools.dotc.typer.Namer.valOrDefDefSig(Namer.scala:1698)
        at dotty.tools.dotc.typer.Namer.defDefSig(Namer.scala:1789)
        at dotty.tools.dotc.typer.Namer$Completer.typeSig(Namer.scala:791)
        at dotty.tools.dotc.typer.Namer$Completer.completeInCreationContext(Namer.scala:934)
        at dotty.tools.dotc.typer.Namer$Completer.complete(Namer.scala:814)
        at dotty.tools.dotc.core.SymDenotations$SymDenotation.completeFrom(SymDenotations.scala:174)
        at dotty.tools.dotc.core.Denotations$Denotation.completeInfo$1(Denotations.scala:187)
        at dotty.tools.dotc.core.Denotations$Denotation.info(Denotations.scala:189)
        at dotty.tools.dotc.core.SymDenotations$SymDenotation.ensureCompleted(SymDenotations.scala:393)
        at dotty.tools.dotc.typer.Typer.retrieveSym(Typer.scala:2989)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3014)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3111)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3184)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3188)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3210)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3256)
        at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:2669)
        at dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$1(Typer.scala:3036)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3040)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3111)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3184)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3188)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3210)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3256)
        at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:2812)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3081)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3112)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3184)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3188)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3300)
        at dotty.tools.dotc.typer.TyperPhase.typeCheck$$anonfun$1(TyperPhase.scala:44)
        at dotty.tools.dotc.typer.TyperPhase.typeCheck$$anonfun$adapted$1(TyperPhase.scala:54)
        at scala.Function0.apply$mcV$sp(Function0.scala:42)
        at dotty.tools.dotc.core.Phases$Phase.monitor(Phases.scala:440)
        at dotty.tools.dotc.typer.TyperPhase.typeCheck(TyperPhase.scala:54)
        at dotty.tools.dotc.typer.TyperPhase.runOn$$anonfun$3(TyperPhase.scala:88)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.typer.TyperPhase.runOn(TyperPhase.scala:88)
        at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:246)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1321)
        at dotty.tools.dotc.Run.runPhases$1(Run.scala:262)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:270)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:279)
        at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:279)
        at dotty.tools.dotc.Run.compileSources(Run.scala:194)
        at dotty.tools.dotc.Run.compile(Run.scala:179)
        at dotty.tools.dotc.Driver.doCompile(Driver.scala:37)
        at dotty.tools.dotc.Driver.process(Driver.scala:197)
        at dotty.tools.dotc.Driver.process(Driver.scala:165)
        at dotty.tools.dotc.Driver.process(Driver.scala:177)
        at dotty.tools.dotc.Driver.main(Driver.scala:207)
        at dotty.tools.dotc.Main.main(Main.scala)
Compilation failed

1 reply

bishabosha Oct 17, 2023
Author

thanks, I suppose that supports my use case which is to test the compiler directly

Gedochao · 2023-10-17T07:27:03Z

Gedochao
Oct 17, 2023
Maintainer

All we get from Bloop on the compiler crash is:

▶ scala-cli crash.scala -v -v -v
(...)
Received onBuildTaskFinish from bloop: TaskFinishParams [
  taskId = TaskId [
    id = "1"
    parents = null
  ]
  eventTime = 1697527445237
  message = "Compiled 'compiler-crash_a69ec373e9-fd842dd7b2'"
  status = ERROR
  dataKind = "compile-report"
  data = {"target":{"uri":"file:/Users/pchabelski/IdeaProjects/scala-cli-tests/compiler-crash/.scala-build/?id=compiler-crash_a69ec373e9-fd842dd7b2"},"errors":0,"warnings":0,"isNoOp":false,"isLastCycle":true}
]
Error compiling project (Scala 3.3.1, JVM)
Received onBuildLogMessage from bloop: LogMessageParams [
  type = ERROR
  task = null
  originId = null
  message = "Unexpected error when compiling compiler-crash_a69ec373e9-fd842dd7b2: 'assertion failed'"
]
Error: Unexpected error when compiling compiler-crash_a69ec373e9-fd842dd7b2: 'assertion failed'
Compilation failed
Compilation failed

It seems Bloop only sends us the error message, which we do show: assertion failed.

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How do I show the stack trace when the compiler crashes #2464

bishabosha Oct 16, 2023

Replies: 2 comments · 1 reply

Gedochao Oct 17, 2023 Maintainer

bishabosha Oct 17, 2023 Author

Gedochao Oct 17, 2023 Maintainer

bishabosha
Oct 16, 2023

Replies: 2 comments 1 reply

Gedochao
Oct 17, 2023
Maintainer

bishabosha Oct 17, 2023
Author

Gedochao
Oct 17, 2023
Maintainer