mercurial: don't load C extensions from PyPy PyPy isn't compatible with Python C extensions. With this patch, the module load policy is automatically to "Python only" when run under PyPy. `hg` and other Python scripts importing mercurial.* modules will run from the source checkout or any installation when executed with PyPy. This should enable people to more easily experiment with PyPy and its potentially significant performance benefits over CPython!