here’s the actual PythonInterpreter that gets used to run setup.py:

PythonInterpreter('/System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7', PythonIdentity('CPython', 2, 7, 10), {('setuptools', '18.0.1'): '/private/var/tmp/_bazel_bstaffin/8c38a28958d9cca0b3bd6c22d0e1b69d/execroot/heron/external/setuptools_whl/file/setuptools-18.0.1-py2.py3-none-any.whl', ('wheel', '0.23.0'): '/private/var/tmp/_bazel_bstaffin/8c38a28958d9cca0b3bd6c22d0e1b69d/execroot/heron/external/wheel_whl/file/wheel-0.23.0-py2.py3-none-any.whl’})