Missing import of trac.util.translation._

[Dave Abrahams <dave@…>]

In trac.admin.web_ui.py, line 83, the name _ is used without previously defining it.

raceback (most recent call last):
  File "/usr/local/lib/python2.4/site-packages/Trac-0.11dev_r5790-py2.4.egg/trac/web/main.py", line 436, in dispatch_request
    dispatcher.dispatch(req)
  File "/usr/local/lib/python2.4/site-packages/Trac-0.11dev_r5790-py2.4.egg/trac/web/main.py", line 221, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/local/lib/python2.4/site-packages/Trac-0.11dev_r5790-py2.4.egg/trac/admin/web_ui.py", line 83, in process_request
    raise HTTPNotFound(_('No administration panels available'))
UnboundLocalError: local variable '_' referenced before assignment

I tried adding the import at the top of the file, but that didn't fix my problem. So then I ended up stomping into every function that uses _ in that way and doing the import there. Whether that's the right fix or overkill is unclear to me. As you can see from ​http://news.gmane.org/find-root.php?message_id=%3c87sl8laxcx.fsf%40grogan.peloton%3e this thread I don't really understand how these differences in behavior between module-scope and function-scope imports arise.

[Christian Boos]

Make sure you're using at least r5773, see:

• source:/trunk/trac/admin/web_ui.py@5773#L33​
• source:/trunk/trac/admin/web_ui.py@5773#L82​
• (or with the 0.11 range notation: source:/trunk/trac/admin/web_ui.py@5773:33,82​)

[Dave Abrahams <dave@…>]

I'm using r5790. I think you've missed my point. For some reason, the import at the top of the file as shown at source:/trunk/trac/admin/web_ui.py@5773#L33​ doesn't work.

[osimons <simon-code@…>]

web_ui.py source code looks fine reading it, but there is something wrong here. I disabled all my panels to make the HTTPNotFound trigger. And it did - same error as in the ticket description. Using r5789.

Here is what solved it for me:

trac/admin/web_ui.py

@@ -77 +77 @@
             return True
 
     def process_request(self, req):
+        global _
         panels, providers = self._get_panels(req)
         if not panels:
             raise HTTPNotFound(_('No administration panels available'))

Strange… Now, why the global keyword is necessary here is beyond me - I have personally never had use for it before, and not seen it anywhere else in the Trac source I think. There is something in the way this is implemented that provides ambiguity with regards to '_'.

Any trac-devs (or others) able to figure this one out?

[Christopher Lenz]

This should be fixed [5805]. The problem was a local variable declaration also using the underscore. We'll have to be more careful about this, and avoid using an underscore for ignored data.