Improve error message when authentication isn't setup yet (instead of traceback)

[jeffwong@…]

I created a new project but I forgot to setup authentication in the Apache config file.

When I try to log in, I get the following error:

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/trac/web/main.py", line 335, in dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.4/site-packages/trac/web/main.py", line 220, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/lib/python2.4/site-packages/trac/web/auth.py", line 95, in process_request
    self._do_login(req)
  File "/usr/lib/python2.4/site-packages/trac/web/auth.py", line 116, in _do_login
    assert req.remote_user, 'Authentication information not available.'
AssertionError: Authentication information not available.

It would be nice to have a friendlier error message like "You can't log in because authentication is not setup yet. Please ask the adminstrator of your Trac system or your system adminstrator to set up authentication."

Another solution might be to hide or disable the login link, but I like the idea of being able to find out what you can do about the situation if authentication is not enabled.

Showing the traceback right now is mystifying to the user. Even for an adminstrator, it takes a bit of work to figure out what caused the problem.

[Matthew Good]

The login link cannot be automatically disabled because Trac has no way of knowing whether you've configured authentication on your server or not.

[sid]

A friendlier error message for this specific case would be nice though. It seems to be quite common. There are 26 tickets on t.e.o. about this error, and nearly 350 hits when doing a ​google search on it.

[Emmanuel Blot]

I think christian has already improved the error message some time ago, see #3839.

Feel free to re-open if you think the message is not explicit enough.