From the moodle.org apache error_log:

Debugging: Error: mdb->get_record() found more than one record!<ul style="text-align: left"><li>line 1255 of /lib/dml/moodle_database.php: call to debugging()</li><li>line 1215 of /lib/dml/moodle_database.php: call to moodle_database->get_record_sql()</li><li>line 1195 of /lib/dml/moodle_database.php: call to moodle_database->get_record_select()</li><li>line 349 of /lib/rsslib.php: call to moodle_database->get_record()</li><li>line 66 of /rss/file.php: call to rss_get_userid_from_token()</li></ul>

This occurs multiple times through out the log