Self-typed inheritance crashing compiler

[jnatten]

Compiler version 3.3.6 / 3.7.2 (mill)

Minimized code

Im not able to produce a very minimal code example, but our repository is open source and this is a branch i will not touch that has this error and the file mention in the compiler error is this one:

ArticleIndexService

which inherits IndexService.scala

which then again inherits BaseIndexService

We are implementing cake-pattern by wrapping our classes with self-typed traits so i assume that is part of the issue.

The command to compile/run tests is ./mill article-api.test

It also works if i change IndexService and BaseIndexService to be abstract classes instead of traits.

The error can be "fixed" if i stop extending IndexService in that one OR if i in IndexService stops extending BaseIndexService OR if i remove every method from BaseIndexService and implement everything in IndexService (Or just replace them with ???).

Output

https://gist.github.com/jnatten/be68f2fd1020a686d37e7c4f733b801a

Expectation

Would expect the compiler to not crash, but rather give me a compile error if there are any errors?

We are in the process of migrating our codebase to scala 3 and when doing so i run into this issue.
We are also considering rewriting our cake pattern stuff to given/using syntax for DI.
Does anyone know if that would work around this issue?

Any feedback would be greatly appreciated.