什么问题？uncaughtException { Error: spawn compass ENOENT

uncaughtException { Error: spawn compass ENOENT at exports._errnoException (util.js:1023:11) at Process.ChildProcess._handle.onexit (internal/child_process.js:193:32) at onErrorNT (internal/child_process.js:359:16) at _combinedTickCallback (internal/process/next_tick.js:74:11) at process._tickCallback (internal/process/next_tick.js:98:9) code: 'ENOENT', errno: 'ENOENT', syscall: 'spawn compass', path: 'compass', spawnargs: [ 'compile', '--no-line-comments', '--relative-assets', '--output-style', 'expanded', '--css-dir', 'stylesheets', '--sass-dir', 'stylesheets', '--images-dir', 'images' ] }