$ git clone -n https://src.fedoraproject.org/rpms/s-nail.git /var/lib/mock/f45-build-35519-695/root/chroot_tmpdir/scmroot/s-nail
Cloning into '/var/lib/mock/f45-build-35519-695/root/chroot_tmpdir/scmroot/s-nail'...
$ git fetch origin af0666bf1d2e5876c7a8de73085d0beb821d0180:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/s-nail
 * [new ref]         af0666bf1d2e5876c7a8de73085d0beb821d0180 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at af0666b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild