I was having issues with the old Scala plugin (http://devnet.jetbrains.net/thread/304000) so I used the release of 2.9.0 as an excuse to bring everything up to date.
I now have IntelliJ 10.5 (today's RC release), Scala 2.9.0 and the nightly build of the Scala plugin.
When I try to compile a brand-new project, I get one compile error for every class in my project (and for generated classes). They look like:
Error: 'Quarter' to /opt/local/foo/out/production/com/test/Foo$.class (No such file or directory)
Anyone know what that means or how to resolve it?
It's possible that my install of the nightly didn't work. Based on the best instructions I could find on installing a nightly build of the plugin, I took the .jar files in the download and dumped them into ~/.IdeaIC10/config/plugins .