Wish: A plugin or option to always show all warnings in incremental builds

[lefou]

I just became aware of the sbt-rewarn plugin for sbt. It internally caches compiler warnings to show all warnings even for files which did not change before a incremental compilation. That is something I always wanted since I started to use the Zinc incremental compiler, as I find it quite annoying that I don't see warnings just because the incremental compiler decided to not re-compile some files. The implementation looks quite easy, it hooks into the Zinc compiler reporter to cache and re-play warnings.

[lefou]

I started a draft:

• Support reporting of all compilation problems #2297

[lefou]

Implemented in Mill 0.11.0-M4