It just means OSX users (like me) have to compile from source - no different from PyTorch. Happy to provide compiled binaries for 10.12, though it's a bit of a chore to get Xcode clang and CUDA to play nice together.
For now–I've thought about getting involved in keeping that going, even trying to set up a travis build. But bazel, I, and C++, we simply don't enjoy the time we spend together.