Right now, both the PC and the builder report the same error with slightly different locations. For example:

object X extends App {

  val s = f("")

  def f(i: Int) = i
}

The PC reports the error. Once the build is triggered, the build error is also reported. Users now see two errors. It is probably best to ignore the error of the PC in this situation and only show it when the build error does not exist.

This is only a problem in the editor and not in the problems view, where only the build errors are reported. This is especially annoying when one want to jump to the next or previous error message with CTRL+. or CTRL+, where the key combination needs to be pressed twice in order to go to the next error.