"Invalid authz configuration" verbose?

Hello,

I have encountered from time to time the problem that someone (or an
script) modified an authz file in such a way that it blocked the access
completely to the repository:

     "Invalid authz configuration"

In all the cases I have seen the problem was due to an undefined group,
something like this:

[groups]
group1 = user1, user2

[/]
group1 = rw
group2 = r

my question is, is there any way to have a better error report of the
problem? I often have problems in some authz files which are very long,
and it is not trivial to find the problematic group.

Do you have any suggestion?

Cheers

-- 
      Alvaro Gonzalez Alvarez IT/PES-IS
      CERN - European Organization for Nuclear Research
      Phone: 0041 22 76 77 118
      1211 Geneva - Switzerland,  CERN  Office: 31/1-026