heroku/heroku-buildpack-php — pull request #27 by pirackr (2013-08-17 08:23:01+00:00)
Title: export path for composer post-cmd 

Whenever composer run a post-install-cmd, they couldn't found php (because php binary doesn't appear in any PATH entries), so I have added PATH to php and LD_LIBRARY_PATH (for mcrypt extention).