Naked except statements catch subclasses of BaseException which
can occur anywhere (i.e. KeyboardInterrupt).
Unexpected issues can occur when the exception happens during the
loading of a module. The python interpreter doesn't know about a
module's failed load and does not remove it from sys.modules. This
is particularly a problem on AppEngine where python will think the
module is loaded but in fact the module load has failed.
Signed-off-by: Armin Ronacher <firstname.lastname@example.org>