Installing a Gem From a Git Repository Subdirectory using Bundler


Update (2018-05-07): My PR to bundler-site has been accepted so the :glob option can now be found on the official Bundler Docs. 😊

Sometimes projects, such as the Cloud Foundry Copilot service include their Ruby client gems within subdirectories of the main project itself. While under active development, it can be useful to install the gem directly from the Git repository. Bundler makes this pretty easy for gems that have standalone repos, but there is no clear way to include a gem that is nested deep within a repo. Fortunately, the poorly documented glob parameter can help. 😊

For example, the cf-copilot gem above can be included in a Gemfile like this:

# Gemfile
gem 'cf-copilot', git: '', branch: 'master', glob: 'sdk/ruby/*.gemspec'

Just give it a glob path to the gem’s .gemspec file that is relative to the repository’s root and bundler will handle the rest!