I was setting up a WebDAV folder on Mac OS X and I ran into the following error when starting up Apache.
dyld: /usr/sbin/httpd Undefined symbols:
/usr/sbin/apachectl: line 171: 4554 Trace/BPT trap $HTTPD -t
It turns out when using the PHP module from Marc Liyanage's site the ordering of the modules list is important. So instead of just uncommenting the two LoadModule and AddModule lines for the dav_module, they need to be moved below the PHP module.
That's it. Add the
DAV On and any other directives you like in the Directory of choice and you've got DAV setup. Get more information about WebDAV here.