'Can the `mod_path` be ignored (i.e. it was determined that it
could not contain a valid widget description, for instance the
module does not have a valid description and was not changed from
the last discovery run).'

def cache_can_ignore(self, mod_path, distribution=None):

    mod_path = fix_pyext(mod_path)
    if (not os.path.exists(mod_path)):
        return True
    mtime = os.stat(mod_path).st_mtime
    if (mod_path in self.cached_descriptions):
        entry = self.cached_descriptions[mod_path]
        return ((entry.mtime == mtime) and (entry.exc_type == WidgetSpecificationError))
    else:
        return False
