$ git clone -n https://src.fedoraproject.org/rpms/grc.git /var/lib/mock/f40-build-2691010-68120/root/chroot_tmpdir/scmroot/grc
Cloning into '/var/lib/mock/f40-build-2691010-68120/root/chroot_tmpdir/scmroot/grc'...
$ git fetch origin 15dbfe2ccc72f960e0fe7a989c5841363540871e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/grc
 * [new ref]         15dbfe2ccc72f960e0fe7a989c5841363540871e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 15dbfe2 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild