If you ever wondered why, despite all your efforts and Goole-jistsu, you still couldn't get W3TC to detect your local memcached install, well. You haven't googled enough 😉
The hat trick is to swap 127.0.0.1 for localhost in /etc/memcached.conf:
# Specify which IP address to listen on. The default is to listen on all IP addresses # This parameter is one of the only security measures that memcached has, so make sure # it's listening on a firewalled interface. -l 127.0.0.1 # <=== change this to: -l localhost # TA-DAAAA
It took me some three days to eventually figure it out. But hey, I spend most of my life on a dishwasher. What do I know about internets?