@codeblock, not sure if you're still around but I think you wrote the original version of this? This diff looks OK to me but I don't have this stuff installed either and I'm not sure I can figure out how to test it properly.

I'll see if I can set up a basic Scala project to test these changes.

Sounds good. If you don't get to it in the near future or it's a pain I'm happy to just pull this.

OK so there are a few things that are really wrong with this "linter":

1. It's not really a linter, it's ultimately calling sbt compile and raising any warnings/errors to ArcanistScalaSBTLinter. This makes it very slow.
2. AFAIK, sbt compile can't be run on a single file (which makes sense). This means that (at least in its current form) if I have two files, good.scala and bad.scala then arc lint -- good.scala will raise errors in bad.scala.
3. I have no idea why the canRun logic exists. Whilst some projects may have those directories/files, it doesn't appear to be a prerequisite. I was able to use sbt without either of those files (with a simple "Hello World" project).

IMO, this linter should be deprecated. It appears that there are true Scala linters out there (such as Scalastyle and I would personally prefer to support a true linter than a compiler.