A third option is to just revert hg4963:cdfb1a3fb56f for the v1.5.1
release and migrate to setuputils for the next release...

As far as I can tell the 'develop' command available in setuptools is
mainly used for doing a pseudo install of a package so that it appears
to be installed but still points to the original code to make it easier
for development/testing/debugging. This functionality probably isn't
really that useful in a release tarball.

Reading up a bit on distutils/setuptools it seems that distutils is all
but deprecated in favour of setuptools. Here is a good summary of the
"current" state of python packaging tools:

 
http://stackoverflow.com/questions/6344076/differences-between-distribute-distutils-setuptools-and-distutils2#14753678

As mentions on stackoverflow the official documentation[1] references
the Python Packaging User Guide[2] which recommends setuptools over
distutils (see the footnotes[3] for the reasoning)

[1] https://docs.python.org/2/distutils/
[2] https://packaging.python.org/en/latest/current/
[3] https://packaging.python.org/en/latest/current/#id13