How can Bundler/Gemfile be configured to use different gem sources during development?

Question

I have a Sinatra application that requires another gem I'm developing locally. I'm having trouble configuring Bundler to use my local gem code during development but my vendored gem code in production.

Ideally I could do something like this, but Bundler doesn't allow you to specify the same gem twice:

# Doesn't work:
group :development do
  gem 'awesome', :path => "~/code/awesome"
end

group :production do
  gem 'awesome', :path => "vendor/gems/awesome-0.0.1"
end

In the meantime I've resorted to manually vendoring the gem & updating the gem source in the Gemfile every single time I deploy, which is quite a hassle. My workflow is this:

1. Point to my local gem during development (gem 'awesome', :path => "~/code/awesome")
2. When ready to deploy, unpack gem into vendor/gems
3. Update Gemfile to point to vendored gem (gem 'awesome', :path => "vendor/gems/awesome-0.0.1")
4. Run bundle install (to update Gemfile.lock)
5. Deploy code
6. Return to step 1.

What a hassle! I'd like to do something cleaner than simply writing Rake tasks to automate my current setup.

What's the best workflow for this scenario?

Answer 1

There is a new feature that allows to do that, by simply specyfing local.gem_name config option, like:

bundle config local.rack ~/path/to/local/rack

This only works if the gem has a git repo and branch specified in the Gemfile.

See thr Bundler docs for more details: http://bundler.io/v1.3/bundle_config.html