Mysql 5.6 server via MacPorts won't start

Mysql 5.6 server via MacPorts won't start

I've been happily using MacPorts' mysql5 and mysql5-server. Now it's time
to upgrade. I followed standard procedure, but the server won't start.
sudo port unload mysql5
sudo port install mysql56 mysql56-server mysql_select
sudo port select -set mysql mysql56
sudo port load mysql56-server
No errors. When I run ps aux | grep sql I see it's not running. I tried
setting the socket in my.conf and running mysql5_install_db (but that
seems specific to the older package). File permissions look correct.
There's no mysql error log yet. How do I get this server started?