Comment by somat

Honestly the cddl being incompatible with the gpl is one of the weirder statements to come out of the fsf. It comes up every time the cddl is mentioned but no one really knows why they are incompatible, it is basically "the fsf says they are incompatible" and when really pressed, they dithered until 2016 then came up with some hand waving that the incompatibility is some minutia as to what scope each license applies to.

The whole thing smells of some FSF agenda to me. if you ship a cddl file in your gpl project it is still a gpl licensed project and the cddl file is still a cddl licensed file.