No install link for sub theme of sub theme In my D8 site I have Magazine Lite, a sub theme of Classy. Magazine Lite is installed. 

In web/themes/custom I have a theme installed that in its .info.yml file names Magazine Lite as its base theme.

On the Appearance tab, instead of an install link is the message:


  This theme requires the base theme Magazine Lite to operate correctly


In what way does it require the base theme beyond the base theme being present and installed?
Copied the base theme's info file and changed 'name' to 'base theme'. But the base theme entry needs to be the machine name of the theme, whereas the name is a descriptive name.