Gotcha when deploying to heroku with a forked gem

So we were deploying to heroku and we have a gem as part of project thats forked from original and heroku didnt like it at all and we got an error like so ```bash Removing .DS_Store files remote: -----> Ruby app detected remote: -----> Compiling Ruby/Rails remote: -----> Using Ruby version: ruby-2.0.0 remote: -----> Installing dependencies using 1.9.7 remote: Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin -j4 --deployment remote: Fetching gem metadata from https://rubygems.org/............. remote: Fetching version metadata from https://rubygems.org/... remote: Fetching dependency metadata from https://rubygems.org/.. remote: Fetching git@github.com:siassaj/acts_as_follower.git remote: Host key verification failed. remote: fatal: Could not read from remote repository. remote: Please make sure you have the correct access rights remote: and the repository exists. remote: Retrying git clone 'git@github.com:siassaj/acts_as_follower.git' "/tmp/build_aab7506f5342f75413d3d85d01e2a558/vendor/bundle/ruby/2.0.0/cache/bundler/git/acts_as_follower-5ebd9d15f4ab98d51b4735c6146a547d602764cb" --bare --no-hardlinks --quiet due to error (2/3): Bundler::Source::Git::GitCommandError Git error: command `git clone 'git@github.com:siassaj/acts_as_follower.git' "/tmp/build_aab7506f5342f75413d3d85d01e2a558/vendor/bundle/ruby/2.0.0/cache/bundler/git/acts_as_follower-5ebd9d15f4ab98d51b4735c6146a547d602764cb" --bare --no-hardlinks --quiet` in directory /tmp/build_aab7506f5342f75413d3d85d01e2a558 has failed. ``` In our gem file we had ```ruby gem 'acts_as_follower', git: "git@github.com:siassaj/acts_as_follower.git" ``` Now this left us scratching our heads as haven't seen this issue before. After some reading we found the issue The git@github.com:… URL is the writable SSH version, which requires authentication with an SSH key connected to a GitHub account that has write access to the repository. The git://github.com/… URL is the public, read-only version. Since the gem you're using is in a public GitHub repository, you can also use this shorthand in your Gemfile: So we changed our gem to to below and all good again in the world of development ```ruby gem 'acts_as_follower', github: "siassaj/acts_as_follower" ```