We have seen intermittent TestAllocObjectArrays.java#aggressive failures on x86_64, aarch64 and PPC64le since JDK 19. (Also TestAllocIntArrays.java#iu-aggressive and TestAllocIntArrays.java#aggressive.)

jtr file tells us the following:

command: main -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xmx1g -Xms1g -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot -XX:+ShenandoahVerify TestAllocObjectArrays
reason: User specified action: run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xmx1g -Xms1g -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot -XX:+ShenandoahVerify TestAllocObjectArrays
Mode: othervm [/othervm specified]
elapsed time (seconds): 3.295
----------configuration:(0/0)----------
----------System.out:(1/34)----------
For random generator using seed:
----------System.err:(34/2342)----------
java.lang.ExceptionInInitializerError
at java.base/sun.util.cldr.CLDRLocaleProviderAdapter.<clinit>(CLDRLocaleProviderAdapter.java:60)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:383)
at java.base/java.lang.Class.forName(Class.java:376)
at java.base/sun.util.locale.provider.LocaleProviderAdapter.forType(LocaleProviderAdapter.java:187)
at java.base/sun.util.locale.provider.LocaleProviderAdapter.findAdapter(LocaleProviderAdapter.java:287)
at java.base/sun.util.locale.provider.LocaleProviderAdapter.getAdapter(LocaleProviderAdapter.java:258)
at java.base/java.text.DecimalFormatSymbols.getInstance(DecimalFormatSymbols.java:181)
at java.base/java.util.Formatter.getDecimalFormatSymbols(Formatter.java:2021)
at java.base/java.util.Formatter.getZero(Formatter.java:2029)
at java.base/java.util.Formatter$FormatSpecifier.localizedMagnitude(Formatter.java:4526)
at java.base/java.util.Formatter$FormatSpecifier.print(Formatter.java:3366)
at java.base/java.util.Formatter$FormatSpecifier.printInteger(Formatter.java:3051)
at java.base/java.util.Formatter$FormatSpecifier.print(Formatter.java:3010)
at java.base/java.util.Formatter.format(Formatter.java:2781)
at java.base/java.io.PrintStream.implFormat(PrintStream.java:1366)
at java.base/java.io.PrintStream.format(PrintStream.java:1345)
at java.base/java.io.PrintStream.printf(PrintStream.java:1244)
at jdk.test.lib.Utils.getRandomInstance(Utils.java:511)
at TestAllocObjectArrays.main(TestAllocObjectArrays.java:202)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:1596)
Caused by: java.lang.NullPointerException: Cannot invoke "sun.util.locale.BaseLocale.getVariant()" because "base" is null
at java.base/java.util.Locale.forLanguageTag(Locale.java:1802)
at java.base/sun.util.cldr.CLDRBaseLocaleDataMetaInfo.<clinit>(CLDRBaseLocaleDataMetaInfo.java:41)
... 24 more

Note that the test runs with -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot and SoftReferences are involved (LocaleObjectCache uses SoftReferences, used by printf method called in getRandomInstance(Utils.java:511)).