How can I specify a local gem in my Gemfile?

Question

I'd like Bundler to load a local gem. Is there an option for that? Or do I have to move the gem folder into the .bundle directory?

Solution 1

I believe you can do this:

gem "foo", path: "/path/to/foo"

Solution 2

In addition to specifying the path (as Jimmy mentioned) you can also force Bundler to use a local gem for your environment only by using the following configuration option:

$ bundle config local.GEM_NAME /path/to/local/git/repository

This is extremely helpful if you're developing two gems or a gem and a rails app side-by-side.

Note though, that this only works when you're already using git for your dependency, for example:

# In Gemfile
gem 'rack', :github => 'rack/rack', :branch => 'master'

# In your terminal
$ bundle config local.rack ~/Work/git/rack

As seen on the docs.

Solution 3

You can also reference a local gem with git if you happen to be working on it.

gem 'foo',
  :git => '/Path/to/local/git/repo',
  :branch => 'my-feature-branch'

Then, if it changes I run

bundle exec gem uninstall foo
bundle update foo

But I am not sure everyone needs to run these two steps.

Solution 4

In order to use local gem repository in a Rails project, follow the steps below:

1. Check if your gem folder is a git repository (the command is executed in the gem folder)

   git rev-parse --is-inside-work-tree
   

2. Getting repository path (the command is executed in the gem folder)

   git rev-parse --show-toplevel
   

3. Setting up a local override for the rails application

   bundle config local.GEM_NAME /path/to/local/git/repository
   

   where GEM_NAME is the name of your gem and /path/to/local/git/repository is the output of the command in point 2

4. In your application Gemfile add the following line:

   gem 'GEM_NAME', :github => 'GEM_NAME/GEM_NAME', :branch => 'master'
   

5. Running bundle install should give something like this:

   Using GEM_NAME (0.0.1) from git://github.com/GEM_NAME/GEM_NAME.git (at /path/to/local/git/repository) 
   

   where GEM_NAME is the name of your gem and /path/to/local/git/repository from point 2

6. Finally, run bundle list, not gem list and you should see something like this:

   GEM_NAME (0.0.1 5a68b88)
   

   where GEM_NAME is the name of your gem

---

A few important cases I am observing using:

Rails 4.0.2  
ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-linux] 
Ubuntu 13.10  
RubyMine 6.0.3

• It seems RubyMine is not showing local gems as an external library. More information about the bug can be found here and here
• When I am changing something in the local gem, in order to be loaded in the rails application I should stop/start the rails server

• If I am changing the version of the gem, stopping/starting the Rails server gives me an error. In order to fix it, I am specifying the gem version in the rails application Gemfile like this:

  gem 'GEM_NAME', '0.0.2', :github => 'GEM_NAME/GEM_NAME', :branch => 'master'
  

Solution 5

You can reference gems with source:

source: 'https://source.com', git repository (:github => 'git/url') and with local path

:path => '.../path/gem_name'.

You can learn more about [Gemfiles and how to use them] (https://kolosek.com/rails-bundle-install-and-gemfile) in this article.

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Comments

[Automatico]

I am having issues with this because I am using BUNDLE_PATH (building a package for distribution). When doing what you suggested, or Jimmy's answer, it only does a using, and not actually installing to my BUNDLE_PATH folder. I was not able to figure this out, any help?

[mahemoff]

A hard-coded path is fine for a quick hack session, but bloudermilk's local gem solution is more effective for projects under version control. It lets you keep checking in both projects - gem and project using the gem - such that others can don't have to check out the gem source or share the same paths.

[davetapley]

Note this won't work with a gemspec, per discussion here.

[alxndr]

To disable the local override: bundle config --delete local.GEM_NAME

[Dan]

You can make this slightly cleaner by using a .gitignored symlink to your local gem in your project directory -- that way you can use source control on both projects separately and others can do the same without having an identical directory structure.

[Epigene]

I had to remove version directive from the gem line to get this to work.

[Leo]

If you would like to use a different branch in development from production, you also have to set bundle config disable_local_branch_check true or Bundler will complain about the branch. Be careful with this though, as the checks are supposed to stop incorrect commits getting into Gemfile.lock. Docs here: bundler.io/v1.12/git.html

[Jason R]

Something to watch out for might be Spring. If you are using a local path for your gem you could notice cached versions of your local gem like I did in rails console. If it doesn't seem like your local gem changes are being picked up try spring stop to see if it is indeed the issue.

[Jason R]

Adding the local gem path to config/spring.rb seems to help pickup your local gem changes after restarting rails console/server.

[Cyzanfar]

Way better way of doing it this here: rossta.net/blog/…

[Andy Baird]

This is a perfectly fine way of doing it if you are testing local development of a gem on a larger project. In this case, this is the "better" way to do it then having to push to a repository to test local changes.

[Ramses]

this is great, but is not that convenient if you're actively developing the gem... because you'll need to commit every change & bundle uninstall <gem> && bundle install , for every change you want reflected on your app

[Joshua Pinter]

NOTE: You cannot specify the branch to use when using path, so make sure the correct branch is checked out in the local file system when doing this.

[KenB]

This doesn't work, generates an error: Only gems with a git source can specify a branch.

[Benjineer]

Note that the path provided in the bundle command should be the root directory of the other gem's source code