Cython called via cythonize in, e.g. pyproject.toml, creates ELF debug entries with a nondetermistic temporary directory such as "/tmp/.tmp-propcache-pep517-11hza083/src/src/propcache/_helpers_c.c:9725"
Our notes about issues affecting packages are stored in notes.git and are targeted at packages in Debian in 'unstable/amd64' (unless they say otherwise).