Gem file with git remote failing on heroku push

Use this GitHub URL instead: git://github.com/Dakuan/client_side_validations.git

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:

gem 'client_side_validations', :github => 'Dakuan/client_side_validations'

See the Bundler Git documentation for more information.