sosedoff/capistrano-unicorn — pull request #2 by irohiroki (2011-11-09 02:09:02+00:00)
Title: let unicorn read the right Gemfile on USR2

since unicorn knows Gemfile path in its real (not symbolic) one, it continues to use old Gemfile after receiving USR2.
my patch fixes this issue by specifying Gemfile in `current_path' (symbolic) via BUNDLE_GEMFILE environment variable.