Comment 1 for bug 1290562

This seems to fail consistently on workers in rax but succeed in hpcloud. We saw it briefly weeks ago, but the release of setuptools 2.2 seemed to cause it to cease. The most recent occurrences seem to possibly coincide with Saturday's release of setuptools 3.1, but that could simply be a red herring. So far I've been unable to identify the particular difference discriminating this failure between these systems.

I have narrowed it down to a simple means of recreating on rax: within a pypy virtualenv, use pip to upgrade setuptools and mccabe together on the same command line. Examples...

Working in hpcloud: http://paste.openstack.org/show/73058/

Failing in rax: http://paste.openstack.org/show/73060/

I discussed this with Alex Gaynor just now, and we agree that this feels like some sort of order of execution strangeness in pip which is getting triggered by hash ordering differences in different systems/interpreters rather than being a PyPy-specific bug.