Non-Kotlin extensions crash the build when using Kotlin DSL + Kotlin plugins

[octylFractal]

Expected Behavior

I should be able to use extensions written in languages other than Kotlin.

Current Behavior

The build crashes with this message:

* What went wrong:
Unresolved class: class edu.wpi.first.gradlerio.frc.FRCPlugin$_apply_closure8

Context

This stopped working in Gradle 5.6, due to this being added. It assumes that concreteClass is a Kotlin type, and converts it to a KClass, but when the visibility is resolved, it obviously cannot find the Kotlin metadata and throws the above error. It should probably detect if it is indeed a Kotlin type, and otherwise detect via normal Java mechanisms.

Note: it's not quite as simple as simply adding a non-Kotlin plugin, and I'm not exactly sure why. It seems like the accessor class path isn't attempted for generation unless I apply it as a dependency of my Kotlin-DSL-based plugin. Regardless, the following project reliably reproduces the issue.

Steps to Reproduce

Run the build for this project:
https://github.com/kenzierocks/gradle-kdsl-gen-accessors-non-kotlin-types-issue

Your Environment

Build scan URL: https://scans.gradle.com/s/5cm4zyadrsscs

[eskatos]

Thanks for the report @kenzierocks, I can confirm the regression.

The ProjectSchemaProvider chokes on Groovy closures added as extensions, like in:

https://github.com/wpilibsuite/GradleRIO/blob/304f416e374874fd73b994999aa9fab6cbf7e4a0/src/main/groovy/edu/wpi/first/gradlerio/frc/FRCPlugin.groovy#L76-L78

[eskatos]

Fixed in 6516f3a for Gradle 5.6.3 and in aa0d471973449263c4219e10dffd4ca0b08a28fdfor for Gradle 6.0

Thanks again for the report @kenzierocks