heroku/heroku-buildpack-ruby — pull request #69 by dpiddy (2013-03-07 19:31:43+00:00)
Title: Cache parsed bundle

Currently we're fetching and setting up bundler many times during the detect and compile phases which slows things down.

This at least gets it down to one fetch + setup for each phase. Might consider vendoring bundler to prevent needing to fetch it at all.