astropy/astropy — pull request #2061 by mdboom (2014-02-07 16:56:39+00:00)
Title: Display a better error message if the _wcs C extension can not load.

Since we can't do anything at all with `astropy.wcs` if the C extension didn't build or can't load, we should just bail (unless we are in `_ASTROPY_SETUP_` which still requires the module to be imported).

This is sort of a side issue to #2057.