像Scout和Compass.app之类的应用程序都捆绑了自己的Ruby版本，即使您在计算机上安装了gems从这些应用程序进行编译时不会安装它们。

Apps like Scout and Compass.app come bundled with their own versions of Ruby so even though you installed the gems on your computer they are not installed when compiling from those apps.

这里是如何使Compass.app在计算机上使用Ruby版本。打开首选项，然后选中自定义。请注意，您的路径可能有所不同：

Here is how to make Compass.app use the version of Ruby on your computer. Open preferences and check "Custom". Note your path may be different: