$ git clone -n https://src.fedoraproject.org/rpms/screengrab.git /var/lib/mock/f45-build-35699-698/root/chroot_tmpdir/scmroot/screengrab
Cloning into '/var/lib/mock/f45-build-35699-698/root/chroot_tmpdir/scmroot/screengrab'...
$ git fetch origin b4447fffacc599104a1cae72868948635af8f023:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/screengrab
 * [new ref]         b4447fffacc599104a1cae72868948635af8f023 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b4447ff Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild