$ git clone -n https://src.fedoraproject.org/rpms/kscreen.git /var/lib/mock/f42-build-862524-170850/root/chroot_tmpdir/scmroot/kscreen
Cloning into '/var/lib/mock/f42-build-862524-170850/root/chroot_tmpdir/scmroot/kscreen'...
$ git fetch origin 6e5acb854022ecbb2e3e06fe02fddfcbf53deef3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kscreen
 * [new ref]         6e5acb854022ecbb2e3e06fe02fddfcbf53deef3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6e5acb8 6.2.4