mvn versions:display-dependency-updates throws llegalArgumentException: Comparison method violates its general contract!

[RalfNaujokat]

Using Maven 3.9.9 with different JDKs (Oracle Java 21, GraalVM 21/23) on Linux

StackTrace is:

` == BEGIN ==

[ERROR] Failed to execute goal org.codehaus.mojo:versions-maven-plugin:2.17.1:display-dependency-updates (default-cli) on project libraries: Unable to acquire metadata for dependencies java.util.stream.ReferencePipeline$2@629591d0: java.lang.IllegalArgumentException: Comparison method violates its general contract! -> [Help 1] org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:versions-maven-plugin:2.17.1:display-dependency-updates (default-cli) on project libraries: Unable to acquire metadata for dependencies java.util.stream.ReferencePipeline$2@629591d0: java.lang.IllegalArgumentException: Comparison method violates its general contract! at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:333) at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174) at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75) at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162) at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:193) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:180) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:572) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144) at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642) at java.lang.Thread.run (Thread.java:1583) Caused by: org.apache.maven.plugin.MojoExecutionException: Unable to acquire metadata for dependencies java.util.stream.ReferencePipeline$2@629591d0: java.lang.IllegalArgumentException: Comparison method violates its general contract! at org.codehaus.mojo.versions.DisplayDependencyUpdatesMojo.execute (DisplayDependencyUpdatesMojo.java:477) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126) at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328) at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174) at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75) at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162) at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:193) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:180) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:572) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144) at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642) at java.lang.Thread.run (Thread.java:1583) Caused by: org.codehaus.mojo.versions.api.VersionRetrievalException: Unable to acquire metadata for dependencies java.util.stream.ReferencePipeline$2@629591d0: java.lang.IllegalArgumentException: Comparison method violates its general contract! at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupDependenciesUpdates (DefaultVersionsHelper.java:533) at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupDependenciesUpdates (DefaultVersionsHelper.java:543) at org.codehaus.mojo.versions.DisplayDependencyUpdatesMojo.execute (DisplayDependencyUpdatesMojo.java:412) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126) at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328) at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174) at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75) at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162) at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:193) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:180) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:572) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144) at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642) at java.lang.Thread.run (Thread.java:1583) Caused by: java.util.concurrent.ExecutionException: java.lang.IllegalArgumentException: Comparison method violates its general contract! at java.util.concurrent.FutureTask.report (FutureTask.java:122) at java.util.concurrent.FutureTask.get (FutureTask.java:191) at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupDependenciesUpdates (DefaultVersionsHelper.java:526) at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupDependenciesUpdates (DefaultVersionsHelper.java:543) at org.codehaus.mojo.versions.DisplayDependencyUpdatesMojo.execute (DisplayDependencyUpdatesMojo.java:412) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126) at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328) at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174) at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75) at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162) at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39) at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:193) at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:180) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:572) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144) at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642) at java.lang.Thread.run (Thread.java:1583) Caused by: java.lang.IllegalArgumentException: Comparison method violates its general contract! at java.util.ComparableTimSort.mergeHi (ComparableTimSort.java:870) at java.util.ComparableTimSort.mergeAt (ComparableTimSort.java:487) at java.util.ComparableTimSort.mergeForceCollapse (ComparableTimSort.java:426) at java.util.ComparableTimSort.sort (ComparableTimSort.java:222) at java.util.Arrays.sort (Arrays.java:1108) at java.util.Arrays.sort (Arrays.java:1302) at java.util.ArrayList.sort (ArrayList.java:1804) at java.util.Collections.sort (Collections.java:145) at org.apache.maven.repository.internal.DefaultVersionRangeResolver.resolveVersionRange (DefaultVersionRangeResolver.java:160) at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveVersionRange (DefaultRepositorySystem.java:260) at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupArtifactVersions (DefaultVersionsHelper.java:282) at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupDependencyUpdates (DefaultVersionsHelper.java:553) at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lambda$lookupDependenciesUpdates$4 (DefaultVersionsHelper.java:522) at java.util.concurrent.FutureTask.run (FutureTask.java:317) at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144) at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642) at java.lang.Thread.run (Thread.java:1583)

== END == `

[RalfNaujokat]

Google took me to: https://stackoverflow.com/questions/71027480/java-exception-exception-java-lang-illegalargumentexception-comparison-method

and then to https://stackoverflow.com/questions/8327514/comparison-method-violates-its-general-contract

so finally starting as export MAVEN_OPTS="-Djava.util.Arrays.useLegacyMergeSort=true" ; mvn versions:display-dependency-updates

at least is a workaround.

[andrzejj0]

Can you provide a minimal project (pom.xml) to run the goal on in order to reproduce the problem?

[RalfNaujokat]

sorry, but i this happened only on one very big project with tons of dependencies. i have no clue which one triggers the error.

[andrzejj0]

Does this happen with other Maven versions on this particular project?

[andrzejj0]

Looking at the stack trace, it seems that it's an error within Resolver (so, Maven) rather than in the plugin itself. Compare especially:

Caused by: java.lang.IllegalArgumentException: Comparison method violates its general contract!
at java.util.ComparableTimSort.mergeHi (ComparableTimSort.java:870)
at java.util.ComparableTimSort.mergeAt (ComparableTimSort.java:487)
at java.util.ComparableTimSort.mergeForceCollapse (ComparableTimSort.java:426)
at java.util.ComparableTimSort.sort (ComparableTimSort.java:222)
at java.util.Arrays.sort (Arrays.java:1108)
at java.util.Arrays.sort (Arrays.java:1302)
at java.util.ArrayList.sort (ArrayList.java:1804)
at java.util.Collections.sort (Collections.java:145)
at org.apache.maven.repository.internal.DefaultVersionRangeResolver.resolveVersionRange (DefaultVersionRangeResolver.java:160)
at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveVersionRange (DefaultRepositorySystem.java:260)
at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupArtifactVersions (DefaultVersionsHelper.java:282)
at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lookupDependencyUpdates (DefaultVersionsHelper.java:553)
at org.codehaus.mojo.versions.api.DefaultVersionsHelper.lambda$lookupDependenciesUpdates$4 (DefaultVersionsHelper.java:522)

DefaultVersionRangeResolver::resolveVersionRange:

   List<Version> versions = new ArrayList<>();
   ...
   Collections.sort( versions );   <--------

So, it looks like GenericVersion::compareTo might be the culprit here. To be checked

[andrzejj0]

https://issues.apache.org/jira/browse/MRESOLVER-314 Resolved in Resolver 1.9.5 by maven-resolver#249

[andrzejj0]

@RalfNaujokat please make sure that you're using Maven 3.9.1 or newer. Best if you could provide an (obfuscated, if necessary) output of mvn -X running the goal.

[RalfNaujokat]

Hi.

Sorry that i left you alone with that, i wasn't available over weekend. I was using Maven 3.9.9 when the error occurred.

I will try to reproduce the error and send you a mvn -X output, but to be honest, i'm not very confident that I can still manage that.

greetings Ralf

[andrzejj0]

The issue is coming from Maven itself (we use provided Maven dependencies in plugins), so if you're in fact using 3.9.9 then it's a yet another problem with the GenericVersion::compareTo method. I would invite you to file a bug with Maven itself (project MRESOLVER in the Apache Jira).

The -X (debug) output of Maven will help verifying that. In particular, it's very important to check if there are no "unorthodox" version numbers among your dependency as that's where the comparator is having a problem with.