is not possible:
1. sencha generate theme gray, everything ok
2. copied sencha's gray theme to the new generated sass file : resources/sass/gray/app.scss
3. compass compile, not ok, generated resources/sass/css/app.css instead of resources/css/gray/app.css
4. But tried next step even if 3 is not ok, so inside app/ I try : sencha build theme grayand it writes back : [ERROR] Expected 0 parameters

what's wrong here ? besides the 3 step which is a bug.