Buildout should use pypi mirrors if pypi goes down
Pypi goes down every once in a while, that's a fact.
Buildout dies if pypi is down and leaves your workspace in a broken state.
There's an easy (in theory) fix for this: Use the Pypi mirrors (http://
Both bootstrap and buildout should fall back to the mirrors should the main server not be available!
Being able to change the index in a global config file is not really that useful, since the buildout might run automated (CI for example) and there's noone to switch the index from pypi to a mirror then.