执行结果如下：

F:\localhost\files\css>compass watch --trace >>> Compass is watching for changes. Press Ctrl-C to Stop. [Listen warning]: Listen will be polling for changes. Learn more at https://github.com/guard/listen#polling-fallback. NoMethodError on line ["402"] of D: undefined method `start' for # D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/sass-3.4.9/lib/sass/plugin/compiler.rb:402:in `map' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/sass-3.4.9/lib/sass/plugin/compiler.rb:402:in `listen_to' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/sass-3.4.9/lib/sass/plugin/compiler.rb:338:in `watch' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/lib/compass/sass_compiler.rb:46:in `watch!' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/lib/compass/commands/watch_project.rb:41:in `perform' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/lib/compass/commands/base.rb:18:in `execute' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/lib/compass/commands/project_base.rb:19:in `execute' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/lib/compass/exec/sub_command_ui.rb:43:in `perform!' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/lib/compass/exec/sub_command_ui.rb:15:in `run!' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/bin/compass:30:in `block in ' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/bin/compass:44:in `call' D:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-1.0.3/bin/compass:44:in `' D:/Ruby21-x64/bin/compass:23:in `load' D:/Ruby21-x64/bin/compass:23:in `
'