Fix Bundler with git repo gems in the system path

bundler_git_path_fix.rb

module Bundler
  module Source
    class Git < Path
      def path
        @install_path ||= begin
          if Bundler.requires_sudo?
            Bundler.user_bundle_path.join(Bundler.ruby_scope).join(git_scope)
          else
            Bundler.install_path.join(git_scope)
          end
        end
      end

      def load_spec_files
        super
      rescue PathError, GitError
        if @install_path == Bundler.user_bundle_path.join(Bundler.ruby_scope).join(git_scope) &&
            Bundler.requires_sudo? && !Bundler.settings[:disable_shared_gems]
          # if the install_path is set to the user's bundle path, the system install 
          # path requires sudo, and we haven't explicity disabled shared gems, retry 
          # lading with the system install path
          @_install_path_original = @install_path
          @install_path = Bundler.install_path.join(git_scope)
          retry
        end
        if @_install_path_original
          # ensure that we get the proper/original error message if we have retried
          @install_path = @_install_path_original
          @_install_path_original = nil
        end
        raise GitError, "#{to_s} is not checked out. Please run `bundle install`"
      end

      private

      def git_scope
        "#{base_name}-#{shortref_for_path(revision)}"
      end
    end
  end
end