Ok, the failure was that it does not really work with CMake 4. After installing CMake 4 inside my chroot, the build failed for me as well. It works in Salsa CI because we still have CMake 3 in unstable. Maybe we should ask Timo to upload it for unstable already so that testing fixes of CMake 4 related bugs is easier. Since I already did the upload, I'm going to see if I can fix it... Thanks.