Scala.js breaks scoverage

[darkfrog26]

In my projects that use Scala.js I keep running into problems using scoverage. In the current project I'm getting this error:

[error] /home/mhicks/projects/open-source/youi/core/js/src/main/scala/io/youi/http/WebSocketUtil.scala:6: Found a dangling UndefinedParam at Position(file:/home/mhicks/projects/open-source/youi/core/js/src/main/scala/io/youi/http/WebSocketUtil.scala,8,13). This is likely due to a bad interaction between a macro or a compiler plugin and the Scala.js compiler plugin. If you hit this, please let us know.

I'm using the sbt-scoverage plugin and if I run sbt clean test everything works, but if I run sbt clean coverage test I get the above error. If I just run against JVM projects everything is fine.

[darkfrog26]

Looks like this has been seen by others: scala-js/scala-js#2631

[ryan-williams]

Here's a Travis build showing it.

I'm surprised I'd not seen it before, I think I've run coverage on many cross-built projects. Maybe I'm mistaken about that, or something about specific projects causing this issue to occur.