For some reason our site can receive but not send trackbacks. I opened up the trackback module and put in some trace code, and here's the sequence of calls leading up to the failure (ordered from outermost to innermost):
...
_trackback_send
_trackback_ping
_trackback_build_content
node_build_content
node_invoke_nodeapi('view')
pathauto_nodeapi
_pathauto_include
require_once("$pathauto_path/pathauto.inc");
The first call to require_once() in _pathauto_include() fails to return. I'm new to PHP and the Drupal framework, and I don't know how to dig any further than this. Things I've verified:
1. We can send trackbacks when the pathauto module is disabled.
2. The value of $pathauto_path is correct when the call to require_once fails, and pathauto.inc exists in this directory.
3. The call to require_once("$pathauto_path/pathauto.inc") in _pathauto_include() does not fail in other contexts. Normally _pathauto_include() returns without problems.
The only thing that I can think of is that there might for some reason be contention on pathauto.inc, though I don't know how to check this. Does anyone know what's going on or have any suggestions for how I might investigate further?
