D:\trunk\web>grunt serverRunning "server" taskRunning "clean:server" (clean) taskRunning "concurrent:server" (concurrent) taskRunning "coffee:dist" (coffee) taskRunning "compass:dev" (compass) taskWarning:You need to have Ruby and Compass installed a

D:\trunk\web>grunt server
Running "server" task
Running "clean:server" (clean) task
Running "concurrent:server" (concurrent) task
Running "coffee:dist" (coffee) task
Running "compass:dev" (compass) task
Warning:You need to have Ruby and Compass installed and in your system PATH for
Use --force to continue.

把你的ruby和compress的安装目录加入path环境变量中即可.