[kchod]

Scala support: yes, add using Skylark. Definitely let us know if you run into any rough edges, Skylark is a work-in-progress.

For multiple repos: there's no command line flag, but you could change the WORKSPACE file to use http://bazel.io/docs/build-encyclopedia.html#local_repositor.... Unfortunately, this may be of limited use to you. At the moment it's optimized/bugged to assumed that your local repos don't change, so it won't rebuild them (this is great for things like the JDK and gcc, but not so much for actual in-development repos). Feel free to file feature requests for any functionality you need, I'll be working on this a lot over the next couple months.