Unsupported class file major version 65

[str8y]

Please check the User Guide before submitting "how do I do 'x'?" questions!

Shadow Version

8.1.1

Gradle Version

8.3

Java Version

17

Expected Behavior

It definitely worked with the same configuration a couple of weeks ago

Actual Behavior

Seems that any of the dependencies was updated to a version built with Java 21 or why does this issue suddenly occurs?

java.lang.IllegalArgumentException: Unsupported class file major version 65
at org.objectweb.asm.ClassReader.(ClassReader.java:199)
at org.objectweb.asm.ClassReader.(ClassReader.java:180)
at org.objectweb.asm.ClassReader.(ClassReader.java:166)
at org.objectweb.asm.ClassReader.(ClassReader.java:287)
at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:67)
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:484)
at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:72)
at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteNoUnwrapNoCoerce.callConstructor(ConstructorSite.java:105)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:277)
at com.github.jengelman.gradle.plugins.shadow.tasks.ShadowCopyAction$StreamAction.remapClass(ShadowCopyAction.groovy:339)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.codehaus.groovy.runtime.callsite.PlainObjectMetaMethodSite.doInvoke(PlainObjectMetaMethodSite.java:48)
at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:189)
at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:57)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:203)
at com.github.jengelman.gradle.plugins.shadow.tasks.ShadowCopyAction$StreamAction.remapClass(ShadowCopyAction.groovy:317)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.codehaus.groovy.runtime.callsite.PlainObjectMetaMethodSite.doInvoke(PlainObjectMetaMethodSite.java:48)
at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:189)
at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:57)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:194)
at com.github.jengelman.gradle.plugins.shadow.tasks.ShadowCopyAction$StreamAction.visitArchiveFile(ShadowCopyAction.groovy:286)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:107)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:362)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:61)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:194)
at com.github.jengelman.gradle.plugins.shadow.tasks.ShadowCopyAction$StreamAction$_processArchive_closure3.doCall(ShadowCopyAction.groovy:263)

[Goooler]

Duplicate of #894

[str8y]

@Goooler

Are you sure it's a duplicate?
As mentioned, it worked a few weeks ago with exactly the same configuration. I don't want to use Java 21 or a newer gradle version. I just want to understand what was changed, that the current config doesn't work anymore

[Goooler]

Your classes are built on Java 21 for now. If you want to pin the byte code level to lower, try to declare sourceCompatibility and targetCompatibility.

[str8y]

Again, I haven't changed anything in my gradle configuration. What do you mean with "your classes"?
We only use Java 17. My classes are built on Java 17.
sourceCompatibility and targetCompatibility are also set to 17.
The shadow plugin just stopped working without any changes on my side and apparently no changes on the shadow plugin side.
That's why I think it must be one of the used dependencies by the shadow plugin.
With the libraries, that I actually shadow, I don't see a problem, because we are using them anyway in our Java 17 environment.

[Goooler]

Your shadowed dependencies may contain Java 21 classes, you can try out my fork to check if it works for you, see #876 (comment). As a workaround, you can also try #876 (comment).

[str8y]

I will give your fork a try but I still think that the issue is related to a dependency used by the shadow plugin itself.
Because I even get the error when I have something like
shadowJar {
relocate('a', 'b') {}
}

[str8y]

your fork is working...
I still would be interested in the actual issue though...
:)
Thanks for the help so far