刚刚开始运行Guard，我遇到了一个奇怪的问题。一旦我将多个文件添加到concat和uglify中，uglifier就会一直触发。我必须按^ C才能让它停止并抛出以下错误：
ERROR - Guard::Uglify failed to achieve its <run_on_change>, exception was:
ExecJS::RuntimeError:
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/execjs-1.4.0/lib/execjs/external_runtime.rb:142:in `exec_runtime'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/execjs-1.4.0/lib/execjs/external_runtime.rb:28:in `block in exec'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/execjs-1.4.0/lib/execjs/external_runtime.rb:41:in `compile_to_tempfile'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/execjs-1.4.0/lib/execjs/external_runtime.rb:27:in `exec'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/uglifier-1.3.0/lib/uglifier.rb:100:in `compile'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-uglify-0.1.0/lib/guard/uglify.rb:23:in `run_on_change'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:99:in `block in run_supervised_task'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:97:in `catch'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:97:in `run_supervised_task'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:146:in `block in run_first_task_found'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:144:in `each'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:144:in `run_first_task_found'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:79:in `block in run_on_changes'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:175:in `block (3 levels) in scoped_guards'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:174:in `each'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:174:in `block (2 levels) in scoped_guards'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:173:in `catch'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:173:in `block in scoped_guards'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:172:in `each'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:172:in `scoped_guards'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard/runner.rb:72:in `run_on_changes'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard.rb:141:in `block (2 levels) in setup_listener'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard.rb:365:in `block in within_preserved_state'
<internal:prelude>:10:in `synchronize'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard.rb:362:in `within_preserved_state'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/guard-1.7.0/lib/guard.rb:140:in `block in setup_listener'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/listen-0.7.3/lib/listen/listener.rb:212:in `call'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/listen-0.7.3/lib/listen/listener.rb:212:in `on_change'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/listen-0.7.3/lib/listen/listener.rb:221:in `block in initialize_adapter'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/listen-0.7.3/lib/listen/adapter.rb:198:in `call'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/listen-0.7.3/lib/listen/adapter.rb:198:in `report_changes'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/listen-0.7.3/lib/listen/adapter.rb:210:in `poll_changed_dirs'
/Users/joe/.rvm/gems/ruby-1.9.3-p194/gems/listen-0.7.3/lib/listen/adapters/darwin.rb:38:in `block in start'
请注意，代码仍然正确无误且一切正常......但是一旦我点击^ C uglify将不会再次触发。就像我说的那样，我是Guard的新手所以我不知道我做错了什么，如果这是一个带有guard-uglify或Ruby的东西或者只是与Guard本身有关的错误。
几个笔记：
另外，这是我的Guardfile：
guard :concat, type: "js", files: %w(vendor/jquery-1.9.1.min vendor/handlebars vendor/jquery.iosslider.min app), input_dir: "js", output: "js/s.min"
guard 'uglify', :destination_file => "js/s.min.js" do
watch (%r{js/s.min.js})
end
任何帮助非常感谢
答案 0 :(得分：3)
uglifier插件配置为写入正在监视更改的同一文件，从而创建无限循环。您需要使用不同的文件：
guard :concat, {
type: 'js',
files: %w(vendor/jquery-1.9.1.min vendor/handlebars vendor/jquery.iosslider.min app),
input_dir: 'js',
output: 'js/s'
}
guard 'uglify', :destination_file => 'js/s.min.js' do
watch (%r{js/s.js})
end
由于已经报告了后续错误，我看了一下该插件并认识到它已被更新，但没有新的gem被推送到RubyGems。所以看起来创作对插件失去了兴趣。您可以通过更改Gemfile：
gem 'guard-uglify', github: 'pferdefleisch/guard-uglify'
这使它可以在我的机器上运行。说实话，我的工具链里没有那个未完成且没有维护的插件。您可以使用guard-jammit或guard-process来实现相同目标。