TypeError: dist must be a Distribution instance

The only way I was able to solve it was to follow the https://bugs.python.org/file37554/distutils_accomodate_distribution_ducktypes.patch So - I removed /usr/lib/python2.7/distutils/cmd.py and /usr/lib/python2.7/distutils/cmd.pyc ( ran a python setup.py develop - just to make sure it fails and is not using the pyc from somewhere else ) and then recreated /usr/lib/python2.7/distutils/cmd.py - only this time with the changes as shown in the patch. Then when I used python setup.py again - it worked..

This error has to do with a discrepancy between the versions of distutils and setuptools installed on your machine. Upgrading setuptools to the current version is likely to resolve the issue.

EDIT: This solution no longer works for me (and apparently never worked for Jens -- see comment below). What now works for me is to import setuptools before anything else in whatever script I'm calling that leads to this error.

This error is discussed in many issues on GitHub, in many packages, but I find this discussion to be the most informative.