Eli Zaretskii <eliz@gnu.org> writes:

>   . applying this fails compile-tests in the test suite, so I guess
>     some adjustment there is also needed;

Oops!  In the new patch, attached below, I

- adjust the existing legacy Gradle/Kotlin tests and
- add new tests for the non-legacy Gradle/Kotlin warnings/errors.

I also improved the commit message a bit.

>   . you removed the comment with the pointer to kotlin sources, which
>     might be still useful for the legacy format (unless the URL is no
>     longer valid), so please restore that if the pointer can still be
>     useful

Smart!  All right, I did a bit of research, and documented

- the first and last Kotlin version that emits the current format,
- the last Kotlin version that used the legacy format,
- the official Git commit that removed the legacy format,
- the public release date of the current format, and
- the Kotlin class where the current format is defined.

All of it is packed into two short comments.

Rudy