Install a compatible version of setuptools on Python 2.6.

Review Request #9529 — Created Jan. 24, 2018 and submitted — Latest diff uploaded

Information

Review Board
release-2.0.x
9bf8948...

Reviewers

Setuptools dropped Python 2.6 support back in 36.8.0, but up until
fairly recently it still worked. Now that it's definitely off of Python
2.6, we want to make sure we don't accidentally install a newer version
than that when building the package.

Successfully ran setup.py develop on Python 2.6 and 2.7.