$ git clone -n https://src.fedoraproject.org/rpms/compiler-rt18.git /var/lib/mock/f42-bootstrap-3462113-45558/root/chroot_tmpdir/scmroot/compiler-rt18
Cloning into '/var/lib/mock/f42-bootstrap-3462113-45558/root/chroot_tmpdir/scmroot/compiler-rt18'...
$ git fetch origin 827d43c4a1cd08667071d7c1df596eae72627ba9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/compiler-rt18
 * [new ref]         827d43c4a1cd08667071d7c1df596eae72627ba9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 827d43c Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild