Fast shared memory user data cache for PHP Formula was removed
Last versions were
php54-yac requires the following formula to be installed:
autoconf 2.69 Automatic configure script builder

Recent formula history

Mike McQuaid Deprecate tap.
pd4d10 php-5{3-6}-yac 0.9.2
Andreas Braun Add description for yac formula
Andy Blyler fix style issues
Jack Nagel Move abstract classes out of Formula directory

Formula code at GitHub