The copy of memcache.rb in typo’s trunk has the line
$TESTING = defined? $TESTING
at the top. This means that after including memcache, $TESTING is
definitely defined. If we’re testing, it’s true, if not, it’s defined
In the typo code elsewhere, the checks for testing mode only check
$TESTING is defined, not what its actual value is.
This means typo always runs in testing mode!
I believe this is the main reason threaded trackback pings were not