tpope/vim-projectionist — pull request #25 by padde (2014-06-14 10:10:56+00:00)
Title: Warn and exit if required after rails.vim

This situation is problematic because it breaks command in rails.vim such as the
alternate file (`:A`) command. When projectionist.vim is now required after
rails.vim, an error message appears and projectionist will not be loaded.

Also see https://github.com/tpope/vim-rails/issues/330