That was also my initial idea, but then I ran into some issues with the LibRaw build system from git: it only provides a configure.ac file, and running autoconf was giving me some fatal errors.
Before spending time to investigate the issue, I wanted to set-up the appimage to work with a custom LibRaw version, so I picked 0.17.2.
Now I will come back to the git version and try to solve the building issue…