How can I use an older version of Bundler for a Ruby project?

Question

...without uninstalling the latest version.

I'm working on a project that uses Bundler 1.10, but I use Bundler 1.11 for all my other projects. Since this project is on 1.10, whenever I run any bundle commands, my Gemfile.lock changes due to the different formatting introduced by Bundler 1.11.

The only solution I've found so far is running all my commands like so:

bundle _1.10.6_ [command]

(from this answer here: https://stackoverflow.com/a/4373478/1612744)

Is there a better way? I'm using rbenv, not rvm.

Answer 1

You could use the rbenv-gemset plugin. Since an older version of a gem in an rbenv gemset doesn't override a newer version in the default gemset, you'd need to install bundler for each project, which is rather cumbersome.

• Install the plugin (cd ~/.rbenv/plugins; git clone git://github.com/jf/rbenv-gemset.git) OR, if you use homebrew, brew install rbenv-gemset
• gem uninstall -xI bundler
• For each project that can use bundler 1.11,
  • cd to the project
  • echo bundler-1.11 > .rbenv-gemsets ("bundler-1.11" is the name of the gemset)
• In one of those projects, gem install bundler to get the current version, 1.11.*
• For the project that needs bundler 1.10,
  • cd to the project
  • echo bundler-1.10 > .rbenv-gemsets ("bundler-1.10" is the name of the gemset)
  • gem install bundler -v 1.10.6

Answer 2

I ended up solving this with an alias and a bash function. In my ~/.bashrc, I added this:

versioned_bundle() {
  version_file=${PWD}/.bundle/version
  if [[ -r $version_file ]]; then
    version=$(<$version_file)
    bundle _${version}_ "$@"
  else
    bundle "$@"
  fi
}
alias bundle=versioned_bundle

As you can guess from the code, I also added a version file to the .bundle/ directory in my project. That file's contents:

1.10.6

Whenever I run bundle, my shell checks for a version file in the current directory, and if it finds it, runs that version of bundle.

$ cd project-with-old-bundle-version
$ bundle --version
1.10.6
$ cd anywhere-else
$ bundle --version
1.11.2