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KISS yet powerful gem / gemset management for rbenv

rbenv-gemset plugs in to the goodness of rbenv, and brings you gem management that is at once simple, easy to understand and set up (just one file with the simplest format ever!) and then use to do pretty much everything that you really need to with gemsets.

New with v0.4.0: Project gemsets! install gems into a sub-folder in your project directory for easy cleanup later! (or easy customization, or testing)

rbenv-gemset is an extension for the rbenv ruby version manager that allows you to use "gemsets", sandboxed collections of gems. This lets you have multiple collections of gems installed in different sandboxes, and specify (on a per-application basis) which sets of gems should be used.

Error reports and Bug reports: How to ensure that you get help, a.k.a. "How To Ask Questions The Smart Way"

Special Note for RubyMine users!

Table of Contents



Download and extract the latest release (v0.5.10 now!) or clone rbenv-gemset to your $HOME/.rbenv/plugins directory:

$ git clone $HOME/.rbenv/plugins/rbenv-gemset


Package managers are great; but relying on a package manager that wants to tell you what you can and cannot use based on their quick arbitrary decisions about whether public domain software is acceptable... (this first came to my attention in "issue" 93) is NOT acceptable. You should be able to decide for yourself.

Just use git! It works, and is perfectly fine.

Special note for RubyMine users

RubyMine 8 now supports rbenv-gemset. Thanks, guys!


Running rbenv gemset will give you the following help:

rbenv gemset [command] [options]

possible commands are:
  create [version] [gemset]
  delete [version] [gemset]
  init [gemset]

Here is a basic example:

cd my-project

# Set up a default gemset for your project.
# Also will create a `.rbenv-gemsets` file in the current directory.
# NOTE: this will create the gemset under the current ruby version.
rbenv gemset init

# Alternatively, you can provide `rbenv gemset init` with the name of a gemset:
rbenv gemset init [gemset]

# To create a gemset under a specific ruby version:
rbenv gemset create [version] [gemset]

# You can list the existing gemsets by using the following command:
# This should include the most recent gemset you just created.
rbenv gemset list

# You can delete a gemset with the following command:
rbenv gemset delete [version] [gemset]

Usage (the advanced, "neckbeard" version)

In your application directory, create a file named .rbenv-gemsets, with the names of the gemsets that you want to use on separate lines, or separated by whitespace. The first gemset in the list will be the primary gemset, where new gems will be installed.

$ echo -e "my-gemset\nanother-gemset" > .rbenv-gemsets

Now all commands involving gems will use the gemsets that you've specified.

To have gems install into a sub-folder in your project directory for easy removal later (rm -rf project_dir!) / editing / testing, you can use a project gemset. A project gemset has a '.' ("dot") as the first character:

$ echo '.gems' > .rbenv-gemsets

Your gems will then get installed in project/.gems. If you don't want to use a "dot directory" to house your gems but still want to use a project gemset, then do something like this instead:

$ echo './gems' > .rbenv-gemsets

Your gems will then get installed in project/gems.

To see your currently active gemsets, try rbenv gemset active. If you're wondering about that gemset called global at the end, see #59 (comment). TL;DR: if you don't have any actual gemset called global, forget about it! global will not affect you at all. If you just don't like seeing that global at the end, you can add a -global ("minus gemset") to your .rbenv-gemsets file.

The gemset plugin will cause rbenv to search for the .rbenv-gemsets file in the current directory, as well as in all ancestor directories, until either a config file is found or it has gone all the way up to /. If, along the way, a .ruby-gemset file is found instead of .rbenv-gemsets, .ruby-gemset will be used.

Special environment variable tips and tricks

RBENV_GEMSETS: You can use this environment variable when you want to work with a certain gemset (or gemset list!). For a quick install into a certain gemset, for example:

$ RBENV_GEMSETS="global" gem install thin

RBENV_GEMSET_FILE: You have to know what you're doing, but you can set RBENV_GEMSET_FILE to the absolute path of a gemset file if you want to use another gemset file that isn't in any of your ancestor directories. Note that you have to be using the same version of ruby for this to work as expected!

$ RBENV_GEMSET_FILE="$HOME/hplabs/project1/.rbenv-gemsets" rails new newproject

How to Report Issues



Jamis Buck started the project in 2011, and Joe Fiorini took over as maintainer in May 2012. Jeffrey 'jf' Lim is now the current maintainer, and took over in July 2013.


This code is placed in the public domain by the author, Jamis Buck. Use it as you wish. Please prefer good over evil.