Moving to rbenv from rvm

RVM has been a great tool for managing different projects with different ruby versions – for you python folks you may be aware of virtualenv. But that has not come without it’s issues. Setting up Jenkins CI and RubyMine can require some extra setup steps that are a little frustrating sometimes. I’ve started moving all my development environments to rbenv and have been very happy. rbenv is a bit less intrusive and simpler to manage.

Here are the steps I took to make that move. Hopefully this will make things easy when you decide to make the switch.

The steps here assume you’re on a Mac with homebrew. If not, you may need to do some installation from source.

First – blow away rvm.

rvm implode
rm ~/.rvmrc
rm -r ~/.rvm

Install rbenv.

# install rbenv with homebrew
brew install rbenv

Install ruby-build. This plugin gives rbenv the install action to install rubies.

git clone git://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build

Install rbenv-bundler. This will make rbenv bundler aware. Without, you may run into permissions issues because without it ‘gem install bundler’ tries to install into /usr/bin.

git clone git://github.com/carsomyr/rbenv-bundler.git ~/.rbenv/plugins/bundler

Add shims to every shell by adding this line to your .profile or .bashrc

eval "$(rbenv init -)"

And while you’re in there, you might also remove references to rvm. Mine was trying to run ~/.rvm/script/rvm and had ~/.rvm/bin in the PATH. I removed all that and started with a clean shell for the rest.

Install your rubies

rbenv install 1.8.7-p334
rbenv install 1.9.2-p180
# ... add others that you use here

You can run

rbenv install --list

to figure out what rubies ruby-build knows about.

Pick a system ruby

rbenv global 1.9.2-p180

Setup bundler. I’m not certain that you need to do this for each ruby, but I had problems without doing that. So for good measure, and since it only has to happen once:

rbenv shell 1.8.7-p334
gem install bundler
rbenv shell 1.9.2-p190
gem install bundler
rbenv rehash

Tell rbenv that you’ve got new stuff

rbenv rehash

Set rubies for your different levels of usage. You can set global, local, and shell. I primarily use global and local, where global is for the machine, and local is for the projects that I work on.

cd /projects/my-1.8.7-project/
rbenv local 1.8.7-p334
cd /projects/my-1.9.2-project/
rbenv local 1.9.2-p190

That should be it.

You’ll need to re-bundle on your projects but from there on out you should be happily moved onto rbenv.

I’ve only just begun the process. For my development machines, this has been an easy switch. I’m hoping it will help me clean up my config for Jenkins.

Also, keep in mind that if you share projects with RVM users, no problem. These two systems, though they don’t work well together on the same machine, will not conflict across boxes. So you can safely run rbenv while your co-workers use rvm.