with_clean_git_env

# File lib/bundler/shared_helpers.rb, line 75
    def with_clean_git_env(&block)
      keys    = ]GIT_DIR GIT_WORK_TREE]
      old_env = keys.inject({}) do |h, k|
        h.update(k => ENV[k])
      end

      keys.each {|key| ENV.delete(key) }

      block.call
    ensure
      keys.each {|key| ENV[key] = old_env[key] }
    end