ruby-build is an rbenv plugin that provides an rbenv install command to compile and install different versions of Ruby on UNIX-like systems.

You can also use ruby-build without rbenv in environments where you need precise control over Ruby version installation.

Installing ruby-build as an rbenv plugin will give you access to the rbenv install command.

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

This will install the latest development version of ruby-build into the ~/.rbenv/plugins/ruby-build directory. From that directory, you can check out a specific release tag. To update ruby-build, run git pull to download the latest changes.

Installing ruby-build as a standalone program will give you access to the ruby-build command for precise control over Ruby version installation. If you have rbenv installed, you will also be able to use the rbenv install command.

git clone git://github.com/sstephenson/ruby-build.git
cd ruby-build
./install.sh

This will install ruby-build into /usr/local. If you do not have write permission to /usr/local, you will need to run sudo ./install.sh instead. You can install to a different prefix by setting the PREFIX environment variable.

To update ruby-build after it has been installed, run git pull in your cloned copy of the repository, then re-run the install script.

Mac OS X users can install ruby-build with the Homebrew package manager. This will give you access to the ruby-build command. If you have rbenv installed, you will also be able to use the rbenv install command.

This is the recommended method of installation if you installed rbenv with Homebrew.

brew install ruby-build

Or, if you would like to install the latest development release:

brew install --HEAD ruby-build

To install a Ruby version for use with rbenv, run rbenv install with the exact name of the version you want to install. For example,

rbenv install 1.9.3-p327

Ruby versions will be installed into a directory of the same name under ~/.rbenv/versions.

To see a list of all available Ruby versions, run rbenv install --list. You may also tab-complete available Ruby versions if your rbenv installation is properly configured.

If you have installed ruby-build as a standalone program, you can use the ruby-build command to compile and install Ruby versions into specific locations.

Run the ruby-build command with the exact name of the version you want to install and the full path where you want to install it. For example,

ruby-build 1.9.3-p327 ~/local/ruby-1.9.3-p327

To see a list of all available Ruby versions, run ruby-build --definitions.

Pass the -v or --verbose flag to ruby-build as the first argument to see what's happening under the hood.

Ruby 2.0 is incompatible with the version of OpenSSL bundled with Mac OS X. To work around this issue, install OpenSSL using Homebrew instead:

brew install openssl

Then set the CONFIGURE_OPTS environment variable when you build Ruby:

CONFIGURE_OPTS=--with-openssl-dir=`brew --prefix openssl` rbenv install 2.0.0-preview1

Both rbenv install and ruby-build accept a path to a custom definition file in place of a version name. Custom definitions let you develop and install versions of Ruby that are not yet supported by ruby-build.

See the ruby-build built-in definitions as a starting point for custom definition files.

You can set certain environment variables to control the build process.

• TMPDIR sets the location where ruby-build stores temporary files.
• RUBY_BUILD_BUILD_PATH sets the location in which sources are downloaded and built. By default, this is a subdirectory of TMPDIR.
• RUBY_BUILD_CACHE_PATH, if set, specifies a directory to use for caching downloaded package files.
• RUBY_BUILD_MIRROR_URL overrides the default mirror URL root to one of your choosing.
• RUBY_BUILD_SKIP_MIRROR, if set, forces ruby-build to download packages from their original source URLs instead of using a mirror.
• CC sets the path to the C compiler.
• CONFIGURE_OPTS lets you pass additional options to ./configure.
• MAKE_OPTS (or MAKEOPTS) lets you pass additional options to make.

If you have the md5, openssl, or md5sum tool installed, ruby-build will automatically verify the MD5 checksum of each downloaded package before installing it.

Checksums are optional and specified as anchors on the package URL in each definition. (All bundled definitions include checksums.)

ruby-build will first attempt to download package files from a mirror hosted on Amazon S3. If a package is not available on the mirror, if the mirror is down, or if the download is corrupt, ruby-build will fall back to the official URL specified in the defintion file.

You can point ruby-build to another mirror by specifying the RUBY_BUILD_MIRROR_URL environment variable--useful if you'd like to run your own local mirror, for example. Package mirror URLs are constructed by joining this variable with the MD5 checksum of the package file.

If you don't have an MD5 program installed, ruby-build will skip the download mirror and use official URLs instead. You can force ruby-build to bypass the mirror by setting the RUBY_BUILD_SKIP_MIRROR environment variable.

You can instruct ruby-build to keep a local cache of downloaded package files by setting the RUBY_BUILD_CACHE_PATH environment variable. When set, package files will be kept in this directory after the first successful download and reused by subsequent invocations of ruby-build and rbenv install.

The rbenv install command defaults this path to ~/.rbenv/cache, so in most cases you can enable download caching simply by creating that directory.

Both ruby-build and rbenv install accept the -k or --keep flag, which tells ruby-build to keep the downloaded source after installation. This can be useful if you need to use gdb and memprof with Ruby.

Source code will be kept in a parallel directory tree ~/.rbenv/sources when using --keep with the rbenv install command. You should specify the location of the source code with the RUBY_BUILD_BUILD_PATH environment variable when using --keep with ruby-build.

Please see the ruby-build wiki for solutions to common problems.

If you can't find an answer on the wiki, open an issue on the issue tracker. Be sure to include the full build log for build failures.

• Added optional package checksum support. When a package URL is annotated with an MD5 checksum, ruby-build will use it to verify the contents of the downloaded file. Package URLs in all existing definitions have been updated with checksum annotations.
• Added an optional package download cache. When the RUBY_BUILD_CACHE_PATH environment variable is set to a directory of your choice, ruby-build will store downloaded packages there and reuse them for future installations.
• Added mirror support for faster package downloads. Packages on the official ruby-build mirror will be served via S3. You can point ruby-build to your own local package mirror by setting the RUBY_BUILD_MIRROR_URL environment variable.

• Added a definition for Ruby 1.9.3-p327
• Fetch Ruby 2.0.0.dev and 1.9.3.dev via Git instead of Subversion

• Added a definition for Ruby 2.0.0-preview1
• Added a definition for Rubinius 2.0.0-rc1

• Added a definition for JRuby 1.7.0

• Added a definition for Ruby 1.9.3-p286
• Added a definition for JRuby 1.7.0-rc2
• Added a definition for JRuby 1.7.0-rc1
• Added a definition for JRuby 1.6.8
• Added a definition for JRuby 1.5.6
• Fetch Ruby 2.0.0.dev via Subversion instead of Git
• Allow hooks to be defined for rbenv-install

• Added a definition for MagLev 1.1.0-dev from git.
• Added a definition for Ruby 1.8.7-p370. (For those having trouble installing 1.8.7 with newer versions of glibc, please see rbenv#195 (comment).)
• Updated the package URL in the definition for JRuby 1.7.0-preview1.
• Added a definition for JRuby 1.7.0-preview2.
• Updated the Rubinius 2.0.0-dev definition to use the bundled RubyGems version instead of installing its own.
• Added an rbenv uninstall command for removing installed versions.
• Improved the option parsing for ruby-build and rbenv-install so options may be placed in any order, and short options may be combined (e.g. -kv).
• Added a -l/--list option to rbenv install to list all available definitions.
• Added a -v/--verbose option to rbenv install to invoke ruby-build in verbose mode.
• Documented the -k/--keep flag in the command-line help for ruby-build and rbenv install.

• Added definitions for JRuby 1.6.7.2 and 1.7.0-preview1.
• Removed the definition for JRuby 1.7.0-dev. (In general we do not like to remove definitions, but the JRuby team has deleted the 1.7.0-dev package from their servers -- caveat emptor.)
• Added support for specifying the build location with the RUBY_BUILD_BUILD_PATH environment variable.
• Added a -k/--keep flag to ruby-build and rbenv install for keeping the source code around after installation.
• Updated the readme to emphasize installation as an rbenv plugin.

• Improved error messages when dependencies are missing.
• XCode 4.3+ may be used to build 1.9.3-p125 and later.
• Updated all Ruby 1.9.2 and 1.9.3 definitions to RubyGems 1.8.23.
• Added definitions for REE 1.8.7-2012.02 and 1.8.7-2009.10.
• Added definitions for JRuby 1.6.7.
• Added definitions for Ruby 1.9.2-p318, 1.9.2-p320, and 1.9.3-p194.

• Added definitions for REE 1.8.7-2011.12 and 1.8.7-2012.01.
• Added definitions for JRuby 1.6.5.1 and 1.6.6.
• Added definitions for Ruby 1.8.7-p358 and 1.9.3-p125.
• Updated the readme with instructions for installing ruby-build as an rbenv plugin.

• Added a definition for MagLev 1.0.0.
• Added support for overriding make options with the $MAKEOPTS/$MAKE_OPTS environment variable.
• Removed RubyGems installations from JRuby definitions in favor of the bundled RubyGems versions.
• Added a before_install_package hook.
• Added definitions for REE 1.8.7-2009.09 and 1.8.7-2010.01.
• Added definitions for Ruby 1.8.6-p383, 1.8.7-p302 and 1.8.7-p357.
• Updated the JRuby 1.7.0-dev snapshot URL.
• Changed the GCC detector to look for gcc-* anywhere in the $PATH, not just /usr/bin.

• Added a Ruby 1.8.7-p334 definition.
• Renamed the 1.9.4-dev definition to 2.0.0-dev to reflect the new version numbering scheme.
• ruby-build now automatically displays the last 10 lines of the error log, if any, when a build fails.
• Improved the GCC detection routines and added a more helpful error message for Xcode 4.2 users.
• JRuby installation no longer requires the install prefix to exist first.
• You can now pass $CONFIGURE_OPTS to the REE definitions.
• Added a JRuby 1.6.5 definition.
• Added a Ruby 1.9.2-p180 definition.
• Added a Ruby 1.9.3-p0 definition.

• ruby-build now uses the --with-gcc configure flag on OS X Lion.
• Added definitions for REE 1.8.7-2010.02 and 1.8.6-2009.06.
• Modified rbenv-install to run rbenv rehash after installation.
• Added a Ruby 1.9.3-rc1 definition.
• Updated the JRuby defintions to install the jruby-launcher gem.
• Updated the rbx-2.0.0 definition to point to the master branch.
• Added a jruby-1.7.0-dev definition.
• Added a Ruby 1.9.4-dev definition.

• Added an rbx-2.0.0-dev definition for Rubinius 2.0.0 from git.
• Added support for setting ./configure options with the CONFIGURE_OPTS environment variable.
• Added a 1.9.3-dev definition for Ruby 1.9.3 from Git.
• Added support for fetching package sources via Git.
• Added an rbenv-install script which provides an install command for rbenv users.

• Changed the REE definition not to install its default gem collection.
• Reverted a poorly-tested change that intended to enable support for relative installation paths.

• Initial public release.

(The MIT License)

Copyright (c) 2012 Sam Stephenson

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.