Race condition with multiple source generators in a multi module project

I’m a bit at a loss tracking this one down (time constraints) but have created a simple project to replicate the problem:

https://github.com/nefilim/sbtrace

Running compile (on a clean tree) will almost always result in:

[error] source file 'sbtrace/child/target/scala-2.10/src_managed/main/sbt-buildinfo/BuildInfo.scala' could not be found

In larger project I sometimes see a different missing file but it’s usually this generated file (by sbt-buildinfo plugin).

running compile again will complete successfully. In this sample project, disabling the scalabuff generator (by excluding the scalabuffSettings from the child project settings) will prevent this problem from happening, similarly if multi module projects are collapsed to a single project.

Included in the Build.scala are some workarounds I tried but were unsuccessful.

[tjdett]

For those that find this issue thread searching for a way to get sbt-protoc & sbt-buildinfo to play nice:

managedSourceDirectories in Compile += target.value / "protobuf-generated"

PB.targets in Compile := Seq(
  scalapb.gen() -> (target.value / "protobuf-generated")
)

[eed3si9n]

@DustinChaloupka I think generating source into a completely different source like src/main/protobuf-generated usually fixed the issue.