trying to work out what has changed in either mysql5 or WordPress. Or are they ganging up on me?
Alrighty, then. something was not right in the mysql upgrade of yesterday. for some reason (safety?) the mysql_upgrade script doesn’t run and restarting mysql without it means the internal mysql data tables are out of sync with what the engine expects. and it always helps to go for speed: make BUILD_OPTIMIZED=yes BUILD_STATIC=yes. seems a bit more sprightly now . . .