error in travis build with pipenv 4.1.3

[gsemet]

4.1.3 works great on my machine but on the travis build (that install a python 3.x from scratch) there is an error. Previously, the build was good: https://travis-ci.org/Stibbons/subdlsrv/builds/238000358

Now it fails about missing six package. See: https://travis-ci.org/Stibbons/subdlsrv/jobs/238244319

$ pip install -U pip 'pipenv>=4.1.3'
...
    import six
    ImportError: No module named 'six'

Only for 3.4 and 3.6.
3.5 installed successfully pipenv 4.1.3 and finished the build.

Don't understand why. I have worked around it this part in the next build: https://travis-ci.org/Stibbons/subdlsrv/jobs/238245074

$ pip install -U pip 'pipenv>=4.1.3' six
...
Successfully installed

But it failed later on my pipenv install --dev with the same error about missing six package.
Even by manually adding six in the Pipfile and Pipfile.lock with pipenv install six, it still fail on python 3.4 and 3.6: https://travis-ci.org/Stibbons/subdlsrv/jobs/238247638

[gsemet]

Root cause seems related to setuptools 36.0.0.
https://www.reddit.com/r/Python/comments/6elcaa/psa_setuptools_broken_release_36_dont_use_it/

Workaround: pip install 'setuptools<36'

[nateprewitt]

Yep, this was a bug in setuptools, not pipenv. According to pypa/setuptools#1042 this should be resolved now though.