Seemingly random CI failures with java.lang.LinkageError

[psibre]

Somewhat unpredictably, we're seeing random CI failures with this error:

    org.gradle.api.GradleException: Could not inject synthetic classes.
        at org.gradle.initialization.DefaultLegacyTypesSupport.injectEmptyInterfacesIntoClassLoader(DefaultLegacyTypesSupport.java:91)
        at org.gradle.testfixtures.internal.ProjectBuilderImpl.getGlobalServices(ProjectBuilderImpl.java:161)
        at org.gradle.testfixtures.internal.ProjectBuilderImpl.createProject(ProjectBuilderImpl.java:106)
        at org.gradle.testfixtures.ProjectBuilder.build(ProjectBuilder.java:120)
        at org.gradle.testfixtures.ProjectBuilder$build$0.call(Unknown Source)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:115)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:119)
        at de.dfki.mary.voicebuilding.VoiceLicenseExtensionTest.setup(VoiceLicenseExtensionTest.groovy:12)

        Caused by:
        java.lang.RuntimeException: java.lang.LinkageError: loader 'app' attempted duplicate interface definition for org.gradle.api.internal.DynamicObject. (org.gradle.api.internal.DynamicObject is in unnamed module of loader 'app')
            at org.gradle.internal.classloader.ClassLoaderUtils$AbstractClassLoaderLookuper.invoke(ClassLoaderUtils.java:150)
            at org.gradle.internal.classloader.ClassLoaderUtils$LookupClassDefiner.defineClass(ClassLoaderUtils.java:204)
            at org.gradle.internal.classloader.ClassLoaderUtils.define(ClassLoaderUtils.java:78)
            at org.gradle.initialization.DefaultLegacyTypesSupport.injectEmptyInterfacesIntoClassLoader(DefaultLegacyTypesSupport.java:88)
            ... 8 more

            Caused by:
            java.lang.LinkageError: loader 'app' attempted duplicate interface definition for org.gradle.api.internal.DynamicObject. (org.gradle.api.internal.DynamicObject is in unnamed module of loader 'app')
                at java.base/java.lang.ClassLoader.defineClass1(Native Method)
                at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
                at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:878)
                at java.base/java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:710)
                at org.gradle.internal.classloader.ClassLoaderUtils$AbstractClassLoaderLookuper.invoke(ClassLoaderUtils.java:148)
                ... 11 more

Stfw for this only brings up an old bug that was fixed in Gradle v3.0.

[psibre]

Example CI failures:

• https://github.com/marytts/gradle-marytts-voicebuilding-plugin/runs/3059750690?check_suite_focus=true#step:8:233
• https://github.com/marytts/gradle-marytts-voicebuilding-plugin/runs/3059849775?check_suite_focus=true#step:8:230

[psibre]

The stacktrace above is thrown by

Gradle suite > Gradle test > de.dfki.mary.voicebuilding.VoiceLicenseExtensionTest > setup FAILED

The other one by

 Gradle suite > Gradle test > de.dfki.mary.voicebuilding.VoiceExtensionTest > setup FAILED
    java.lang.LinkageError: loader (instance of  sun/misc/Launcher$AppClassLoader): attempted  duplicate class definition for name: "org/gradle/api/internal/DynamicObject"
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:635)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:104)
        at org.gradle.internal.classloader.ClassLoaderUtils$ReflectionClassDefiner.defineClass(ClassLoaderUtils.java:173)
        at org.gradle.internal.classloader.ClassLoaderUtils.define(ClassLoaderUtils.java:78)
        at org.gradle.initialization.DefaultLegacyTypesSupport.injectEmptyInterfacesIntoClassLoader(DefaultLegacyTypesSupport.java:88)
        at org.gradle.testfixtures.internal.ProjectBuilderImpl.getGlobalServices(ProjectBuilderImpl.java:161)
        at org.gradle.testfixtures.internal.ProjectBuilderImpl.createProject(ProjectBuilderImpl.java:106)
        at org.gradle.testfixtures.ProjectBuilder.build(ProjectBuilder.java:120)
        at org.gradle.testfixtures.ProjectBuilder$build$0.call(Unknown Source)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:115)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:119)
        at de.dfki.mary.voicebuilding.VoiceExtensionTest.setup(VoiceExtensionTest.groovy:12)

Maybe something about the way the extensions are implemented is triggering random regressions...? But it's odd that this never appeared before we migrated to GitHub Actions, and now only there...

[psibre]

Another one in https://github.com/marytts/gradle-marytts-voicebuilding-plugin/runs/3059997671?check_suite_focus=true#step:8:233:

 Gradle suite > Gradle test > de.dfki.mary.voicebuilding.VoiceExtensionTest > setup FAILED
    org.gradle.api.GradleException: Could not inject synthetic classes.
        at org.gradle.initialization.DefaultLegacyTypesSupport.injectEmptyInterfacesIntoClassLoader(DefaultLegacyTypesSupport.java:91)
        at org.gradle.testfixtures.internal.ProjectBuilderImpl.getGlobalServices(ProjectBuilderImpl.java:161)
        at org.gradle.testfixtures.internal.ProjectBuilderImpl.createProject(ProjectBuilderImpl.java:106)
        at org.gradle.testfixtures.ProjectBuilder.build(ProjectBuilder.java:120)
        at org.gradle.testfixtures.ProjectBuilder$build$0.call(Unknown Source)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:115)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:119)
        at de.dfki.mary.voicebuilding.VoiceExtensionTest.setup(VoiceExtensionTest.groovy:12)

        Caused by:
        java.lang.RuntimeException: java.lang.LinkageError: loader 'app' attempted duplicate interface definition for org.gradle.api.internal.DynamicObject. (org.gradle.api.internal.DynamicObject is in unnamed module of loader 'app')
            at org.gradle.internal.classloader.ClassLoaderUtils$AbstractClassLoaderLookuper.invoke(ClassLoaderUtils.java:150)
            at org.gradle.internal.classloader.ClassLoaderUtils$LookupClassDefiner.defineClass(ClassLoaderUtils.java:204)
            at org.gradle.internal.classloader.ClassLoaderUtils.define(ClassLoaderUtils.java:78)
            at org.gradle.initialization.DefaultLegacyTypesSupport.injectEmptyInterfacesIntoClassLoader(DefaultLegacyTypesSupport.java:88)
            ... 8 more

            Caused by:
            java.lang.LinkageError: loader 'app' attempted duplicate interface definition for org.gradle.api.internal.DynamicObject. (org.gradle.api.internal.DynamicObject is in unnamed module of loader 'app')
                at java.base/java.lang.ClassLoader.defineClass1(Native Method)
                at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
                at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:878)
                at java.base/java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:710)
                at org.gradle.internal.classloader.ClassLoaderUtils$AbstractClassLoaderLookuper.invoke(ClassLoaderUtils.java:148)
                ... 11 more