Regression in `apache/incubator-pekko`

[WojciechMazur]

Regression found in OpenCB for apache/incubator-pekko - build logs: https://github.com/VirtusLab/community-build3/actions/runs/5557868276/jobs/10152258051

Compiler version

3.3.2-RC nightly
Works in 3.3.1-RC4

Bisect points to 607e4d5

Minimized code

Error is present when referencing type with suffix $ defined in different compilation unit.

// repro_1.scala
object PekkoPduProtobufCodec$

// repro_2.scala
@main def Test = {
  val x = PekkoPduProtobufCodec$
}

Output

Loading Scala 3 binary from /Users/wmazur/projects/dotty/bisect/.scala-build/project_460e25f1fd-574c0e3b00/classes/main/PekkoPduProtobufCodec$.class. It should have been loaded from `.tasty` file. This `.tasty` file is missing. Try cleaning the project to fix this issue.
-- [E119] Type Error: /Users/wmazur/projects/dotty/bisect/main.test.scala:2:10 -
2 |  val x = PekkoPduProtobufCodec$
  |          ^^^^^^^^^^^^^^^^^^^^^^
  |          Java defined class PekkoPduProtobufCodec$ is not a value
2 errors found

Expectation

Should compile

[nicolasstucki]

The Scala spec states that names in the source should not contain $. These are reserved for code generation. Using a name with a $ will have undefined behavior.

[nicolasstucki]

PekkoPduProtobufCodec$ is probably breaking the assumption we need to be able to identify companion module names in 607e4d5#diff-4a6c49a16c6d9551222c4b7648eebeec96009ce5cb851c54fb13e94745a49a80R106-R114

[nicolasstucki]

This issue should be followed on apache/pekko#491. I assume we can close this one.