Late to the conversation sorry. I think this sounds like a good plan. Given we are planning to stick with a vanilla LLVM but just fix the version, it seems it should make it reasonable to have distro’s support this. We can provide binaries easily, but also just a declaration that llvm-3.4 is the current supported version, so please package that and tell GHC where to find it. We already do this in a weak way by checking which version of LLVM the user is using and issuing a warning when it’s one we don’t support. The other aspect that would be very useful is if all the build machines tested with LLVM as well. It’s a lot of work to support LLVM across all the platforms we support and to track changes across both communities. Automated testing of the currently supported LLVM version and LLVM-HEAD would be great. Cheers, David