This test demonstrates how the Presentation Compiler can end up in a stale
state. In a nutshell, by loading and typechecking first A.scala, and then
B.scala, the following compilation error is reported in ``B`` compilation unit:
The default arguments in C (and potentially also the implicit conversion in A) seem to be playing a part.
The code for testing this problem is currently sitting in my own fork:
Let me know if I should open a pull-request against master right away, or wait until a fix is ready (though, the fix and the test code should ideally be part of the same pull request in the end).
We also have a related ticket in the Scala IDE issue tracker: http://scala-ide-portfolio.assembla.com/spaces/scala-ide/support/tickets/1000976.