The analysis cache file should be scala specific already because of that sbt commit. It adds the scala version if crossPaths is set (which is on by default, even without cross building).

```
~/code/play/framework test-templates
❯ ./build "show Play/compileAnalysisFilename"
[info] inc_compile_2.10

~/code/play/framework test-templates
❯ ./build -Dscala.version=2.11.0 "show Play/compileAnalysisFilename"
[info] inc_compile_2.11
```

But if it's triggering a re-compile, then I'll look more closely.