gem_git_reference

# File lib/rubygems/request_set/gem_dependency_api.rb, line 427
  def gem_git_reference options # :nodoc:
    ref    = options.delete :ref
    branch = options.delete :branch
    tag    = options.delete :tag

    reference = nil
    reference ||= ref
    reference ||= branch
    reference ||= tag
    reference ||= 'master'

    if ref && branch
      warn Gem dependencies file #{@path} includes git reference for both ref and branch but only ref is used.
    end
    if (ref||branch) && tag
      warn Gem dependencies file #{@path} includes git reference for both ref/branch and tag but only ref/branch is used.
    end

    reference
  end