Commit validation tests fail on 19ea

[mbien]

The tests were running in headless mode until #4233, while switching the xserver on, I noticed that the commit validation tests started to fail on 19ea (locally reproducible too) (11, 17, 18 works fine).

org.netbeans.modules.ide.kit.VerifySimpleTemplatesTest fails on 19ea with:

    [junit] An error occurred during parsing of '/home/runner/work/netbeans/netbeans/ide/ide.kit/build/test/qa-functional/work/o.n.m.i.k.V/at/Test41.java'. Please report a bug against java/source and attach dump file '/home/runner/work/netbeans/netbeans/ide/ide.kit/build/test/qa-functional/work/userdir0/var/log/Test41.dump'.
    [junit] Caused: java.lang.NullPointerException: Cannot read field "tsym" because "imp.qualid.selected.type" is null
    [junit] 	at com.sun.tools.javac.comp.Check.checkImportedPackagesObservable(Check.java:4031)
    [junit] 	at com.sun.tools.javac.comp.TypeEnter.finishImports(TypeEnter.java:229)
    [junit] 	at com.sun.tools.javac.comp.TypeEnter.complete(TypeEnter.java:214)
    [junit] 	at com.sun.tools.javac.code.Symbol.complete(Symbol.java:682)
    [junit] 	at com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:1410)
    [junit] 	at com.sun.tools.javac.comp.Enter.complete(Enter.java:610)
    [junit] 	at com.sun.tools.javac.comp.Enter.main(Enter.java:587)
    [junit] 	at com.sun.tools.javac.main.JavaCompiler.enterTrees(JavaCompiler.java:1042)
    [junit] 	at com.sun.tools.javac.api.JavacTaskImpl.enter(JavacTaskImpl.java:345)
    [junit] 	at com.sun.tools.javac.api.JavacTaskImpl.enter(JavacTaskImpl.java:282)
    [junit] 	at org.netbeans.modules.java.source.parsing.JavacParser.moveToPhase(JavacParser.java:747)
    [junit] 	at org.netbeans.modules.java.source.parsing.JavacParser.getResult(JavacParser.java:540)
    [junit] 	at org.netbeans.modules.java.source.parsing.JavacParser.getResult(JavacParser.java:141)
    [junit] 	at org.netbeans.modules.parsing.impl.TaskProcessor.callGetResult(TaskProcessor.java:608)
    [junit] 	at org.netbeans.modules.parsing.impl.SourceCache.getResult(SourceCache.java:241)
    [junit] 	at org.netbeans.modules.parsing.impl.TaskProcessor$RequestPerformer.run(TaskProcessor.java:775)
    [junit] 	at org.openide.util.lookup.Lookups.executeWith(Lookups.java:279)
    [junit] 	at org.netbeans.modules.parsing.impl.TaskProcessor$RequestPerformer.execute(TaskProcessor.java:702)
    [junit] [catch] at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:663)
    [junit] 	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:577)
    [junit] 	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
    [junit] 	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1418)
    [junit] 	at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:45)
    [junit] 	at org.openide.util.lookup.Lookups.executeWith(Lookups.java:278)
    [junit] 	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)

The test should be using nb-javac, however it appears as if 19ea javac is used anyway?

netbeans/ide/ide.kit/nbproject/project.properties

Line 43 in d410ca9

requires.nb.javac=true

we saw this before in travis: #3862 (comment)

There is another interesting warnings in the log which might be related to the issue:
17, 18 and 19 all have this, no matter if in headless mode or not:

    [junit] WARNING: Unknown module: jdk.compiler specified to --add-exports
    [junit] WARNING: Unknown module: jdk.compiler specified to --add-opens

The module is obviously there. I suppose the boot classpath is tweaked at some point.

[mbien]

no longer reproducible in #5122 (20ea, nb-javac 19)