In pypa/pip#1924, we find that setuptools is generating the -nspkg.pth files that are bootstrapping the namespace packages, but these files are unnecessary when PEP-420 is present (Python 3.3+) and in fact interfere with pure PEP-420 namespace packages.
It seems the solution may be simple - bypass this behavior when PEP-420 is detected.
In pypa/pip#1924, we find that setuptools is generating the
-nspkg.pthfiles that are bootstrapping the namespace packages, but these files are unnecessary when PEP-420 is present (Python 3.3+) and in fact interfere with pure PEP-420 namespace packages.It seems the solution may be simple - bypass this behavior when PEP-420 is detected.