How to Delete All Ruby Gems

For my day job I’ve been doing a lot of work with Chef, Vagrant, and veewee. All of these tools are continually evolving and, over the course of several weeks time, I’ve updated versions more than once. As a result my set of Ruby Gems was causing some conflicts trying to run vagrant up after using veewee.

To clear things up so that I could make better use of RVM Gemsets to manage what Gems were loaded for a given process, I wanted to delete all Gems installed on my machine. A quick StackOverflow search lead me to this command:

$ [sudo] gem list --no-version | xargs [sudo] gem uninstall -aIx 

While I’ve marked sudo as optional, you should use them as a pair — either have both of them in the command or neither of them.

Running this command didn’t work as expected as it ran afoul of the default gems that are pre-installed with Ruby. Another search lead me to this gem-reset Gist on GitHub.

#!/usr/bin/env ruby
# Remove all gems EXCEPT defaults :)
 
`gem list -d`.split(/\n\n^(?=\w)/).each do |data|
  match = data.match(/(?<name>([^\s]+)) \((?<versions>.*)\)/)
  name = match[:name]
  versions = match[:versions].split(', ')
 
  if match = data.match(/^.*\(([\d\.]*),? ?default\): .*$/)
    next if match[1].empty? # it's the only version if this match is empty
    versions.delete(match[1] || versions[0])
  end
 
  versions.each { |v| system "gem uninstall -Ix #{name} -v #{v}" }
end

This script removes all Gems except the ones marked as default. I forked it and used the wget option to run it. Once the script completed my machine only had the default gems installed.

For each of my Ruby-based projects I added a .ruby-gemset and .ruby-version file specifying the gemset name I wanted and the Ruby version desired. Next I visited each project, checked that the gemset was in use, and ran bundle install to re-install the gems, this time in managed gemsets.

This not only cleared up the gem conflict I had introduced, but has made seeing and managing my installed Gems easier.