> I don't quite understand why you use __PYVENV_LAUNCHER__

When I first developed the venv functionality it was definitely needed, but it looks as if it is not needed now. Perhaps to fix this completely, the following needs to be done, on the assumption that __PYVENV_LAUNCHER__ is no longer needed:

1. Remove the reference to it in distlib, and use sys.executable instead. Once pip incorporates this fix, the Homebrew problem should go away. (I have already made the change in the distlib repo, but this needs to be released in order for pip to consider vendoring it, and then pip needs to be released before Python can incorporate it).

2. Remove references to the environment variable in Python itself, using sys.executable instead.

As the env var was an implementation detail, ISTM it could be removed in a 3.4 point release - would you agree?