admindocs generates an error on the tags page when template tags are included in an egg file

[Mark S. Choate <mark@…>]

Here is the traceback -- the application appears to be looking on the filesystem for a file that doesn't exist.

Traceback:
File "/.../django/core/handlers/base.py" in get_response

92. response = callback(request, *callback_args, callback_kwargs)

File "/.../django/contrib/admin/views/decorators.py" in _checklogin

33. return view_func(request, *args, kwargs)

File "/...o/django/contrib/admindocs/views.py" in template_tag_index

54. load_all_installed_template_libraries()

File "/.../django/contrib/admindocs/views.py" in load_all_installed_template_libraries

313. libraries = [os.path.splitext(p)[0] for p in os.listdir(e) if p.endswith('.py') and p[0].isalpha()]

Exception Type: OSError at /admin/doc/tags/