I just tried a rebuild on a standard docker installation (with Docker from Debian Bullseye, docker.io apt package) and it succeeded, so this at least establishes that self hosted installations are not broken, that is, that launcher rebuild is not reproducibly resulting in failed installations due to an rbtrace dependency problem.
I doubt Docker version is a factor here; rbtrace fails to build inside the container, and that is likely a result of missing or outdated dependencies also inside the container.
Is there any chance your clone of discourse_docker failed to git pull before starting the rebuild, and is thus on an old commit? Can’t hurt to manually git pull and ensure it’s on the latest commit of the main branch.