1.7.0(?): Groovy compiler creates "Template_*.class" files in root app dir.

After upgrading from 1.6 on Java 8 to 1.7 on Java 11/17, I get a lot of files like 'Template_1001.class' etc. in the root of the app dir. This is the case for precompiling as well as normal compilation.

As far as I can tell this is more or less hardwired in the Groovy compiler (to output a file). I am not sure if these files were written somewhere else before?

I tried changing back to 1.6.0/Java8 and it still seems to happen. So I am at a loss for explaining exactly why this happens, since it did not before.

Seen on Ubuntu 22.04 and MacOS.

Can anybody shed some light on where the (temporary?) compiled groovy classes are supposed to go? Or if they should be deleted after writing the other files under /tmp?

See also: StackOverflow issue

Start by reproducing the issue with Play 1.7 on Java 11 or 17, using the compilation paths described in the report, and inspect where Groovy writes Template_*.class files. Done means the compiler's temporary output location is identified and the unwanted root-directory files are either prevented or cleaned up, with the behavior documented or covered by a regression test if the repository provides one.