Using personal gems with Bundle without bothering your colleagues.

Gemfile.dev

# NOTE: When updating gems, the ENV var below will need to be _unset_, so bundler updates the correct lock file.

# NOTE 2: The name 'Gemfile.dev' isn't important - it could be `dev_gems.rb` or anything else.

# SETUP:
# - Set the ENV var: BUNDLE_GEMFILE=Gemfile.dev in your app dir
# - Add Gemfile.dev and Gemfile.dev.lock to your .gitignore (global or local)
# - Copy the rest of this gist into Gemfile.dev (in your project root):

# Copy real lock file to ensure it gets priority
FileUtils.cp("Gemfile.lock", "Gemfile.dev.lock")

# Source real gemfile
eval_gemfile("Gemfile")

# Add personal gems below here
group :development do
  gem "Your Gems Here"
end