I was having some issues with permissions and my AuthzSVNAccessFile, and I was sure I'd made a silly mistake with the file somewhere (and indeed I had). However, whilst trying to figure out what was wrong with my authorisation file, I tried to turn on extra debugging for the parsing of the file, in much the same way as I might do when debugging a mod_rewrite rules set problem. When I googled for how to do this, I found lots of other people asking how they could do the same thing, and a few responses saying that it isn't possible. So, it would be great if we could turn on a debugging flag in our apache config file, and have mod_authz_svn give mod_rewrite style log output to show how it processes the file, and why things match/don't match. That way, when you forget to list someone in a group, or have a typo in your path, it'll be much much easier to find out what you've done wrong...!
Original issue reported by gagravarr