使用--watch时SASS / SCSS LoadError

Question

使用终端中的sass styles.scss test.css --style expanded构建SCSS到CSS输出没有问题。但是，当我尝试使用--watch时，我得到一个LoadError。

这是我使用的输出--trace：

MilleniumFalcon: ~/AuroraFX Studios/Labs/_test +[git:master]
R2-D2:/> sass --watch styles.scss:test.css --style expanded --trace 

  

    

      

Sass正在关注变化。按Ctrl-C停止。       /Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:55:in require': cannot load such file -- rb-fsevent (LoadError) from /Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:55:in require'           从/Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/adapter.rb:207:in load_dependent_adapter' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/adapter.rb:198:in可用吗？           来自/Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/adapter.rb:190:in usable_and_works?' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/adapter.rb:57:in块中的select_and_initialize'           来自/ Library /Ruby / Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/adapter.rb:55:in each' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/adapter.rb:55:in select_and_initialize'           from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/listener.rb:291:in initialize_adapter' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/listener.rb:283:in setup'           from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/vendor/listen/lib/listen/listener.rb:65:in start!' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/lib/sass/plugin/compiler.rb:291:in listen_to'           来自/Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/lib/sass/plugin/compiler.rb:257:in watch' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/lib/sass/plugin.rb:108:in method_missing'           来自/Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/lib/sass/exec.rb:509:in watch_or_update' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/lib/sass/exec.rb:346:in process_result'           来自/Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/lib/sass/exec.rb:43:in parse' from /Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/lib/sass/exec.rb:22:in解析！'           来自/Library/Ruby/Gems/2.0.0/gems/sass-3.3.4/bin/sass:13:in <top (required)>' from /usr/bin/sass:23:in load'           来自/ usr / bin / sass：23：在''