[GROOVY-7387] Trait compilation error: IllegalArgumentException: Comparison method violates its general contract!

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.3.6, 2.4.3
• Fix Version/s: 2.4.5
• Component/s: Compiler
• Environment: Using 32-bit Oracle JDK 1.7.0_45, Groovy 2.4.3 with InvokeDynamic enabled (also reproducible using 2.3.6)
• Assignee: Cédric Champeau
• Reporter: Andy Belsky
• Created: 13/Apr/15 12:39
• Updated: 19/Oct/15 16:05
• Resolved: 13/Sep/15 09:49

Description

The smallest sample I could create is the following.
We've got two Groovy classes, one of which is a trait and another implements that trait.

TestTrait.groovy

package test

trait TestTrait {
  Object userRepository
  Object respondentRepository
  Object surveyStatsRepository
  Object surveyRepository
  Object questionRepository
  Object questionOptionRepository
  Object answerRepository
  Object surveyInvitationRepository
  Object invitationDeliveryRepository
  Object surveyPatternRepository
  Object accessNumberRepository
  Object deliverySubscriberRepository
}

TestClass.groovy

package test

class TestClass implements TestTrait {
}

Then let's compile those using the command line:

$ JAVA_HOME/bin/java -cp ../lib/groovy-all-2.4.3.jar  org.codehaus.groovy.tools.FileSystemCompiler -cp ../lib/groovy-all-2.4.3.jar test/*

This results in the following compiler error:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
General error during canonicalization: Comparison method violates its general contract!

java.lang.IllegalArgumentException: Comparison method violates its general contract!
	at java.util.TimSort.mergeLo(TimSort.java:747)
	at java.util.TimSort.mergeAt(TimSort.java:483)
	at java.util.TimSort.mergeCollapse(TimSort.java:410)
	at java.util.TimSort.sort(TimSort.java:214)
	at java.util.TimSort.sort(TimSort.java:173)
	at java.util.Arrays.sort(Arrays.java:659)
	at java.util.Collections.sort(Collections.java:217)
	at org.codehaus.groovy.transform.trait.TraitComposer.applyTrait(TraitComposer.java:202)
	at org.codehaus.groovy.transform.trait.TraitComposer.doExtendTraits(TraitComposer.java:111)
	at org.codehaus.groovy.control.CompilationUnit$4.call(CompilationUnit.java:188)
	at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1052)
	at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:588)
	at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:566)
	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:543)
	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:522)
	at org.codehaus.groovy.tools.FileSystemCompiler.compile(FileSystemCompiler.java:59)
	at org.codehaus.groovy.tools.FileSystemCompiler.doCompilation(FileSystemCompiler.java:215)
	at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompile(FileSystemCompiler.java:148)
	at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompileWithErrorHandling(FileSystemCompiler.java:178)
	at org.codehaus.groovy.tools.FileSystemCompiler.main(FileSystemCompiler.java:162)

1 error