[jonwayne]

Re:

> Google App Engine's dev_appserver.py completely broke after an update, caused in part by another Google library being installed (protobuf...). Still not sure if the fix was rolled into a release yet...

We've been having a lot of fun with how tricky namespace packages are in Python. We've got a fix in for this issue that should hopefully be in the next SDK release, and we're looking into ways to better isolate dev_appserver from the OS environment.

A simple workaround is to activate an empty virtualenv before running dev_appserver.