gem-src is a gem plugin && rbenv plugin that automatically git clones the gem's source right after every gem install so you can git log, git grep and of course write your patch there!

gem-src is a gem plugin that can be installed via gem install command:

% gem install gem-src

Alternatively, if you're using rbenv, you can install gem-src as an rbenv plugin:

% git clone https://github.com/amatsuda/gem-src.git ~/.rbenv/plugins/gem-src

then you get gem-src enabled for all gem and bundle commands invoked through rbenv.

With this gem plugin installed, every gem install you perform will be followed by automatic git clone of the online repo into the installed gem's "src" directory (if the gemspec's "homepage" property points to a Git repo).

For example, when you execute

% gem i kaminari

and if the gem is installed into ~/.gem/ruby/1.8/kaminari-0.14.1 directory, you'll see Kaminari's full Git repo at ~/.gem/ruby/1.8/kaminari-0.14.1/src directory.

So, the whole directory structure will be like this.

~/.gem/ruby/1.8
├── gems
│   ├── arel-3.0.2
│   │   ├── src
│   ├── gem-src-0.2.0
│   │   ├── src
│   ├── kaminari-0.14.0
│   │   ├── src
│   ├── kaminari-0.14.1
│   │   ├── src
...

Note that you might be cloning the same repository again and again as the gem is updated, or the gem install directory changes. For example, if you're using RVM, each of ~/.rvm/gems/*/gems/* will have it's Git repo inside "src" directory.

Instead of cloning the repo under installed gem directory for each gem install, you can specify one single directory to keep all the cloned source repositories.

This way, git clone will no more be executed per every gem update. This option would be more efficient particularly if you're frequently switching Ruby versions or gemsets, or using bundler with --path per each projects. There are two ways to specify this variable:

1) `GEMSRC_CLONE_ROOT` environment variable
2) add `gemsrc_clone_root` configuration in your .gemrc

For example,

% echo "gemsrc_clone_root: ~/src" >> ~/.gemrc
% gem i active_decorator

will clone the source Git repo into ~/src/active_decorator directory if not exists.

Now, the whole directory structure will look like this.

~
├── src
│   ├── active_decorator
│   ├── capybara
│   ├── i18n_generators
...

You can tell gem-src to rely on ghq command instead of git clone. This requires ghq (https://github.com/motemen/ghq) to be installed, and either of the following two configurations should be made.

1) `GEMSRC_USE_GHQ` environment variable
2) add `gemsrc_use_ghq` configuration in your .gemrc

The directory structure should be like below in this mode.

ghq.root (~/.ghq by default)
├── github.com
│   ├── amatsuda
│   │   ├── database_rewinder
│   │   └── rfd
│   ├── jimweirich
│   │   └── rake
...

When you firstly installed this gem, you might want to type in this command right after the installation.

% gem pristine --all

This will reinstall all the already installed gems, and so will git clone all the repos.

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request