getClass.getResource yields wrong result using 1.9.9 with sbtPlugin := true

[agboom]

steps

See https://github.com/agboom/sbt-resource-test for a repro project.

problem

In a nutshell: when I call getClass.getResource in sbt 1.9.8, the local resource directory URL is returned.

In 1.9.9, a Jar URL is returned: jar:file:~/.sbt/boot/scala-2.12.18/org.scala-sbt/sbt/1.9.9/jansi-2.4.1.jar!/META-INF/versions/9/.

I created a repro, with a GH workflow that reproduces the problem. The workflow run with logs can be found here: https://github.com/agboom/sbt-resource-test/actions/runs/8297335057

For completeness I added both Java 11 and 17 to the build matrix, but the Java version doesn't seem to affect or cause the bug.

expectation

I expect the behavior to be the same as 1.9.8

notes

This is my first issue here, so let me know if you need more information.

Looking at the diff between 1.9.8 and 1.9.9, the Jansi dependency seems to have been updated. Could this be part of the cause? v1.9.8...v1.9.9#diff-ad2642dc77b3679e4ad2c7d3b2f59a2dcf48c1bf5b93a558a4fa44828315a34cR96

[eed3si9n]

Thanks for the bug report with repro project!

[eed3si9n]

Would adding

Test / fork := true

change the result?

[agboom]

@eed3si9n Thanks for your reply and suggestion! Setting fork to true indeed makes it work again. Do you have an idea why this makes a difference? I found some documentation about the limitations of forking, also related to class loading[1][2][3], but not this particular problem.

1: https://www.scala-sbt.org/1.x/docs/Forking.html
2: https://www.scala-sbt.org/1.x/docs/Testing.html#Setup+and+Cleanup
3: https://www.scala-sbt.org/1.x/docs/Running-Project-Code.html