Fix VariantSelection error

[koppor]

Follow-up to #13401

cc @jjohannes

Not sure how to deal with this one

Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure

[jjohannes]

Happy to have a look, but the one line error without context is telling me nothing. Please share how to reproduce the problem.

[koppor]

Ah, yes, sorry. It was too obvious for me as it happens on all runs I did this evening.

Here more context: All runs of binaries in main branch :)

Example: https://github.com/JabRef/jabref/actions/runs/16012116347/job/45171832969

As text:

> Configure project :versions

With

gradlew clean :jablib:classes

I get

> Task :jablib:compileJava FROM-CACHE
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure
Variant Selection Exception: org.gradle.internal.component.resolution.failure.exception.VariantSelectionByAttributesException caused by Resolution Failure: org.gradle.internal.component.resolution.failure.type.AmbiguousVariantsFailure

Hope this helps to be able to reproduce

[jjohannes]

Alright. This is not an error. It is "just" a info log message that is expected (in the current setup) if you run with --info logging. If I just run the command...

gradlew clean :jablib:classes

I do not see it. You most likely enabled info logging somewhere locally?

---

The log message is unfavorably formatted by including the (imo unhelpful) exception. Especially, because I think it is not even the root cause. Unfortunately, this is an issue with Gradle itself and I can't influence it from the plugin I think. We can try to get rid of the situation in the build as I am also interested in improving this at some point. But as I am not sure I can it's not top priority right now. The reason for this is a bit complicated as it is caused by some technical limitations of the Gradle transform system. It would stop if we won't use the feature that inspects the metadata of a certain library to compute the requires for the generated modue-info. The complicated part is getting the metadata into the transform. Sometime that fails (that gives the message) but it does not matter in practice as not all metadata is needed everywhere.

More context:

• Find a way to provide all metadata from all module paths to the transformation – including transitive dependencies from apiElements gradlex-org/extra-java-module-info#186
• https://github.com/gradlex-org/extra-java-module-info?tab=readme-ov-file#how-can-i-avoid-that-the-same-jar-is-transformed-multiple-times-when-using-requirealldefineddependencies

---

My suggestion (apart from just leaving things as they are) would be to not do info logging by default on CI. It is much too noisy and logs a lot of unhelpful information in my mind (related highly voted issue gradle/gradle#2688).

Instead, you can consider activating build scans. This will give you a link to a so called "scan of the build" that will contain more helpful information if you need to analyze some CI build failure. For that, you just need to add a configuration like this to org.jabref.gradle.build.settings.gradle.kts. Feel free to ping me, if you do that and run into any issues.