Switching From Rvm to Rbenv

| posted in: nerdliness 

Since I am reinstalling everything on my machine this week I decided to switch from RVM to rbenv. The biggest reason for the switch is to try something new. Also, rbenv doesn’t fiddle with commands like cd in order to work.

##Removing rvm
Removing rvm is dead simple and necessary as the two won’t co-exist nicely.

$ rvm implode

You may also want to run

$ gem uninstall rvm

##Installing rbenv
I used brew, but you can installing manually too if you like.

$ brew install rbenv
$ brew install ruby-build

ruby-build is a plug-in that allows for easier building of Rubies. Once the two brew commands are done you will need to add the following to your bash or zsh profile:

eval "$(rbenv init -)"

##Getting a Ruby
Downloading and building a Ruby is simple:

$ env CC=/usr/bin/gcc rbenv install 1.9.3-p125 

As of version 4.2, Xcode is LLVM-only and no longer includes GCC. You can install GCC with these binary packages on Mac OS X: https://github.com/kennethreitz/osx-gcc-installer/downloads. Once you’ve got a working gcc compiler in place, the env CC=/usr/bin/gcc specifies its location. And 1.9.3-p125 is the version and patch level of Ruby to compile.

##Displaying Ruby Information in your Prompt
Adding a display of the current Ruby version to my zsh prompt was also easy. I simply embedding the following into my prompt:

rbenv version-name

##Setting Ruby Version Setting the Ruby version to use globally or for a project is also simple. To set the global Ruby version issue a command like this:

$ rbenv global 1.9.3-p125

You can override the global version on a per project basis like so:

$ rbenv local 1.9.2-p290

Both of these commands result in a .rbenv-version file being written that contains the appropriate version indication.

The README file for the rbenv repository on Github lays all of this and more out very nicely.

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Mark H. Nichols

I am a husband, cellist, code prole, nerd, technologist, and all around good guy living and working in fly-over country. You should follow me on Twitter.