Hello, I was just trying to build the GHC-7.6 branch from source and the build failed with type-errors, because the libraries used by GHC have moved on since the release, and "sync all" just gets the most recent version. Is there a "fingerprint" somewhere so that I can checkout the libraries in a suitable form for building 7.6? More generally, I run into this problem all the time with people trying to build the branch I work on, so it really would be nice if we started using sub-modules to keep track of this dependency. I talked to folks at ICFP about this, and one idea was that we could check in the "fingerprint" for a branch into the repo, and track the dependencies this way, but this is exactly what git's submodule machinery does, so it seems pointless to implement the functionality which is already there with a standard interface. Thoughts? -Iavor