Git bisect shows it as the following commit causing the change in behavior:
https://github.com/apache/groovy/commit/09247dd06d None of the mentioned issues have 3.0.23 added to the fix version, so they don't appear in the 3.0.23 release notes, but maybe it wasn't the whole fix that was backported. It's always hard backporting fixes. I suspect it was an unintended side effect of those changes for the static field generics to be flagged. Having said that, it is illegal code in Java, Groovy has just been previously ignoring the error and treating it like "Object". It isn't necessarily obvious from your examples but if you had: class Wrapper<T> { static final T someConst } Then Wrapper<String> and Wrapper<Integer> would have dramatically different ideas about what the shared constant's type is. That's why Java flags it as an error. Earlier Groovy versions just ignored that and treated the constant as type Object. We could debate whether this should have happened in a point release, or only for type checked code, but it's only bad code that is affected, so I don't think we want to change now. I'd suggest just fixing any impacted code, e.g. either changing to an instance field: private final Closure<T> noOpClosure = { T v -> return v } Or use a static factory method (the T method placeholder here is unrelated to the class generics): private static final <T> Closure<T> getNoOpClosure() { { T v -> return v } } Paul. <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free.www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Sat, Apr 12, 2025 at 3:43 AM James Daugherty <jdaughe...@jdresources.net> wrote: > > Hello Everyone, > > Grails recently had a bug report on one of the upgrades in 6.x. > https://github.com/apache/grails-core/issues/14130#issuecomment-2797619047 > > I've narrowed down the issue to the groovy upgrade from 3.0.21 to 3.0.23. In > groovy 3.0.21 the following code compiles: > > class GenericWrapper<T> { > > private static final Closure<T> noOpClosure = { T v -> return v } > > private T obj > > GenericWrapper(T obj) { > this.obj = obj > } > > T transformObj() { > return noOpClosure.call(this.obj) > } > > } > > While in groovy 3.0.23 it fails to compile with: > > org.codehaus.groovy.control.MultipleCompilationErrorsException: startup > failed: > testing.groovy: 3: unable to resolve class T > @ line 3, column 31. > private static final Closure<T> noOpClosure = { T v -> return v } > ^ > > testing.groovy: 3: unable to resolve class T > @ line 3, column 50. > al Closure<T> noOpClosure = { T v -> ret > ^ > > 2 errors > > > Is anyone aware of a known regression in this area? > > Regards, > James >
