Compiling from a clean build produces the expected java class files that run as expected. However, after doing a recompile (even immediately after), the compiler will complain about an enumeration not being part of the a given package though no files have changed.

/home/stratton/josh_projects/potassium/src/com/googlecode/copper/select/Select.scala:8:
error: PolygonMode is not a member of com.googlecode.copper.core
  [scalac] import com.googlecode.copper.core.PolygonMode

The workaround is to rebuild the project from a clean state continuously, but this is much slower than rebuilding only the required classes. It's either a compiler bug in scala itself, or something related to the ant wrapper.

To reproduce:
1) svn checkout http://potassium.googlecode.com/svn/trunk/ potassium-read-only
2) Change the compiler task from 'fsc' to 'scalac'
3) Run 'ant compile' (should run normally)
4) Rerun 'ant compile' (should complain about missing classes)