Slow compile time suggestions?

[seanmcl]

I've got around 2000 lines (in 8 different files) of library code built up. The compile times are becoming significant, around 120 seconds on a new MacBook Pro. Does anyone have advice about keeping these times down? All the time is spent in the type checker.

[seanmcl]

When I run scalac with -Xlog-implicits I see lots of these:

Information:(492, 32) $conforms is not a valid implicit value for com.monsanto.arch.cloudformation.model.Fn::Sub => com.monsanto.arch.cloudformation.model.Token[String] because:
hasMatchingSymbol reported error: type mismatch;
 found   : com.monsanto.arch.cloudformation.model.Fn::Sub <:< com.monsanto.arch.cloudformation.model.Fn::Sub
 required: com.monsanto.arch.cloudformation.model.Fn::Sub => com.monsanto.arch.cloudformation.model.Token[String]
            Resource = Some(Seq(

I wonder if there's a way to short circuit some of this search.