Agree, isn't the difference between method #1 and method #2 precisely the reason that Bundler has a distinction between Gemfile and Gemfile.lock? http://bundler

Agree, isn't the difference between method #1 and method #2 precisely the reason that Bundler has a distinction between Gemfile and Gemfile.lock? http://bundler.io/v1.3/rationale.html http://bundler.io/v1.3/rationale.html Programmers want to handle and edit method #1, but sane deployment or collaboration requires tracking resolved versions via method #2. The Gemfile contains the top-level dependencies that the app needs; the Gemfile.lock ensures that everybody developing or deploying is using the same gem versions for top-level and resolved transitive dependencies. Periodically one can `bundle update` to upgrade gem versions: http://bundler.io/man/bundle-update.1.html http://bundler.io/man/bundle-update.1.html It does continue to surprise me that distinctions like these are not handled by Python tooling, which has this absolutely sordid history around packaging, which continues aplomb in the wheel vs. egg wars... http://lucumr.pocoo.org/2014/1/27/python-on-wheels/ http://lucumr.pocoo.org/2014/1/27/python-on-wheels/