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The following are instructions for using the ruby mise core plugin. This is used when there isn't a git plugin installed named "ruby".

If you want to use asdf-ruby then use mise plugins install ruby GIT_URL.

The code for this is inside the mise repository at ./src/plugins/core/


The following installs the latest version of ruby-3.2.x (if some version of 3.2.x is not already installed) and makes it the global default:

mise use -g [email protected]

Behind the scenes, mise uses ruby-build to compile ruby from source. You can check its README for additional settings and some troubleshooting.


ruby-build already has a handful of settings, in additional to that mise has a few extra configuration variables:

  • MISE_RUBY_INSTALL [bool]: Build with ruby-install instead of ruby-build
  • MISE_RUBY_APPLY_PATCHES [string]: A list of patches (files or URLs) to apply to the ruby source code
  • MISE_RUBY_VERBOSE_INSTALL [bool]: Show verbose output during installation (passes --verbose to ruby-build)
  • MISE_RUBY_BUILD_OPTS [string]: Command line options to pass to ruby-build when installing
  • MISE_RUBY_INSTALL_OPTS [string]: Command line options to pass to ruby-install when installing (if MISE_RUBY_INSTALL=1)
  • MISE_RUBY_DEFAULT_PACKAGES_FILE [string]: location of default gems file, defaults to $HOME/.default-gems

Default gems

mise can automatically install a default set of gems right after installing a new ruby version. To enable this feature, provide a $HOME/.default-gems file that lists one gem per line, for example:

# supports comments
bcat ~> 0.6.0 # supports version constraints
rubocop --pre # install prerelease version

.ruby-version and Gemfile support

mise uses a .tool-versions or .mise.toml file for auto-switching between software versions. However it can also read ruby-specific version files .ruby-version or Gemfile (if it specifies a ruby version).

Create a .ruby-version file for the current version of ruby:

ruby -v > .ruby-version

Manually updating ruby-build

ruby-build should update daily, however if you find versions do not yet exist you can force an update:

mise cache clean
mise ls-remote ruby

Licensed under the MIT License. Maintained by @jdx and friends.