Classloader changed in quarkus 2.1.0 (regression from 2.0.1) for optaplanner/drools with smallrye (but not resteasy)

[ge0ffrey]

Describe the bug

The drools ANC compiler fails in 2.1.0 (not in 2.0.1) on optaplanner's activemq-quarkus quickstart
because the classloader changed.

Before (2.0.1):

After (2.1.0):

The strange thing is, that it doesn't fail for any of the other quickstarts (those use resteasy and sometimes hibernate, this one uses smallrye).
Comparing the dependency tree between 2.0.1 and 2.1.0 shows nothing besides the quarkus version change that could explain this.

Expected behavior

A successful test with the reproducer below.

Actual behavior

2021-07-30 16:29:06,337 WARN  [org.acm.sch.mes.TimeTableMessagingHandler] (ForkJoinPool.commonPool-worker-3) Error during processing a solver request (1).: org.drools.ancompiler.CouldNotCreateAlphaNetworkCompilerException: Cannot create Compiled Alpha Network
        at org.drools.ancompiler.CompiledNetworkSource.newCompiledNetworkInstance(CompiledNetworkSource.java:80)
        at org.drools.ancompiler.CompiledNetworkSource.createInstanceAndSet(CompiledNetworkSource.java:66)
        at org.drools.ancompiler.KieBaseUpdaterANC.lambda$inMemoryUpdate$0(KieBaseUpdaterANC.java:72)
        at java.base/java.util.HashMap$Values.forEach(HashMap.java:976)
        at org.drools.ancompiler.KieBaseUpdaterANC.inMemoryUpdate(KieBaseUpdaterANC.java:70)
        at org.drools.ancompiler.KieBaseUpdaterANC.run(KieBaseUpdaterANC.java:52)
        at org.drools.ancompiler.KieBaseUpdaterANC.generateAndSetInMemoryANC(KieBaseUpdaterANC.java:99)
        at org.optaplanner.core.impl.score.stream.drools.DroolsConstraintSessionFactory.buildKieBaseFromModel(DroolsConstraintSessionFactory.java:85)
        at org.optaplanner.core.impl.score.stream.drools.DroolsConstraintSessionFactory.buildSession(DroolsConstraintSessionFactory.java:126)
        at org.optaplanner.core.impl.score.director.stream.DroolsConstraintStreamScoreDirectorFactory.newConstraintStreamingSession(DroolsConstraintStreamScoreDirectorFactory.java:50)
        at org.optaplanner.core.impl.score.director.stream.DroolsConstraintStreamScoreDirector.resetConstraintStreamingSession(DroolsConstraintStreamScoreDirector.java:75)
        at org.optaplanner.core.impl.score.director.stream.DroolsConstraintStreamScoreDirector.setWorkingSolution(DroolsConstraintStreamScoreDirector.java:67)
        at org.optaplanner.core.impl.solver.scope.SolverScope.setWorkingSolutionFromBestSolution(SolverScope.java:215)
        at org.optaplanner.core.impl.solver.AbstractSolver.solvingStarted(AbstractSolver.java:80)
        at org.optaplanner.core.impl.solver.DefaultSolver.solvingStarted(DefaultSolver.java:200)
        at org.optaplanner.core.impl.solver.DefaultSolver.solve(DefaultSolver.java:174)
        at org.acme.schooltimetabling.messaging.TimeTableMessagingHandler.lambda$solve$0(TimeTableMessagingHandler.java:79)
        at java.base/java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1736)
        at java.base/java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1728)
        at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
        at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
        at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
        at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)
        at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183)
Caused by: java.lang.NoSuchMethodException: org.drools.ancompiler.Compiledorg_acme_schooltimetabling_domain_LessonNetwork31008790748.<init>(org.drools.core.spi.InternalReadAccessor, java.util.Map)
        at java.base/java.lang.Class.getConstructor0(Class.java:3349)
        at java.base/java.lang.Class.getDeclaredConstructor(Class.java:2553)
        at org.drools.ancompiler.CompiledNetworkSource.newCompiledNetworkInstance(CompiledNetworkSource.java:77)
        ... 23 more

How to Reproduce?

git clone https://github.com/kiegroup/optaplanner-quickstarts.git
cd optaplanner-quickstarts
git checkout development
cd technology/java-activemq-quarkus
gedit pom.xml // Switch it to 2.1.0.Final
mvn clean install -DskipTests
cd solver
mvn test -Dtest=TimeTableMessagingHandlerTest#solve

Output of uname -a or ver

No response

Output of java -version

No response

GraalVM version (if different from Java)

No response

Quarkus version or git rev

No response

Build tool (ie. output of mvnw --version or gradlew --version)

No response

Additional information

Reproduced on multiple machines (Radovan, Geoffrey, Luca).
Zulip discussion: https://quarkusio.zulipchat.com/#narrow/stream/187038-dev/topic/2.2E1.2E0.20Classloading.20regressions

[quarkus-bot]

/cc @Christopher-Chianelli, @Ladicek, @jmartisk, @phillip-kruger, @radcortez, @rsynek

[ge0ffrey]

@stuartwdouglas Did the classloader for smallrye but not resteasy change in quarkus 2.1?

[stuartwdouglas]

This was caused by ae9a634