Supertuxkart included non-free images. This is "supertux" images.
supertux image used "Superman" logo.
It is not distributable, Its non-free.
1. Remove non-free images and rebuild.
2. Replace fedora free (fedora acceptable licensed) images.
3. Remove fedora repos.
4. contact copyright/trademark owner.
Blocking FE-Legal, This is license problem.
Debian bug (http://bugs.debian.org/757648) is closed, and upstream bug (https://github.com/supertuxkart/stk-code/issues/1446) is closed.
I reported trisquel this bug. (https://trisquel.info/en/issues/12151)
How it this bug current status ?
Is this problem is resolved ?
And, Do you have legal (Copyright/Trademark) problem ?
This could go either way, but I'm inclined to say that this use probably falls on the acceptable side of the line. Obviously, if DC disagrees and sends us a C&D, we'll respond appropriately.