How to switch from rvm to rbenv
I have had a few issues with rvm recently, both when installing gems and activating them. After trying to reinstall the problematic gems, then a number of solutions the internet recommended, going as far as reinstalling the version of Ruby, I decided to try my luck with rbenv instead. If you too have come to this conclusion, then here’s how to make the switch. If you’re wondering what the benefits of switching might be, this document in the rbenv repo is for you.
We’ll start by uninstalling rvm. A cli command is provided for this very purpose…
$ rvm implode
…however it failed to complete for me. It removed ~/.rvmrc and /etc/rvm, but didn’t delete ~/.rvm so I went and did that manually. To remove the last traces of rvm, open ~/.profile and delete the line(s) pertaining to it then restart your shell.
After making sure homebrew is up to date ($ brew update), run the following two commands to install first rbenv, then ruby-build. Ruby-build is a plugin for rbenv that allows it to compile and install different versions of Ruby.
$ brew install rbenv
$ brew install ruby-build
With those installed, we can move on to configuration.
In the configuration file for your shell of choice (~/.profile, ~/.zshrc, ~/.bash_profile, etc), add the following to load rbenv automatically then re-source the file or restart your shell.
eval "$(rbenv init -)"
Now to install a version of Ruby. You can get a list of all of the available versions with $ rbenv install -l. If you decide on, for example, 2.3.1 then run the following followed by the rehash command. Rehashing needs to be done whenever you install a new version of Ruby or a gem that provides commands. You can optionally set rehashing to be done automatically with the rehash gem.
$ rbenv install 2.3.1
$ rbenv rehash
To use the chosen version globally, run this.
$ rbenv global 2.3.1
Last but not least, we’ll setup Bundler to manage dependencies. At this point you can also install any other gems you want globally, for example rails andpg.
$ gem install bundler
$ brew install rbenv-bundler
$ rbenv rehash
The first command installs Bundler, the second installs another rbenv plugin which will remove the need for you to type bundle exec prior to each command.
In your global .gitignore, add the following lines (if they aren’t already there) to avoid committing the files Bundler creates to a repo.
.bundle
vendor/bundle
With all of that done, you’re now in a position to get back to your projects. To use a specific Ruby version within one project, you can do this.
$ rbenv local 2.3.1
Of course, you’ll want your dependencies. Install them by running bundler.
$ bundle install