$ git clone -n https://src.fedoraproject.org/rpms/rust-primal-slowsieve.git /var/lib/mock/f40-build-2073634-49358/root/chroot_tmpdir/scmroot/rust-primal-slowsieve
Cloning into '/var/lib/mock/f40-build-2073634-49358/root/chroot_tmpdir/scmroot/rust-primal-slowsieve'...
$ git fetch origin 787a03ff9b16d2563e91c6992976876d07d1b62b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-primal-slowsieve
 * [new ref]         787a03ff9b16d2563e91c6992976876d07d1b62b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 787a03f Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild