$ git clone -n https://src.fedoraproject.org/rpms/gnome-flashback.git /var/lib/mock/f40-build-2639248-66346/root/chroot_tmpdir/scmroot/gnome-flashback
Cloning into '/var/lib/mock/f40-build-2639248-66346/root/chroot_tmpdir/scmroot/gnome-flashback'...
$ git fetch origin 96ad356fcb45fc2c423bdd21baedb52afd4693e4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-flashback
 * [new ref]         96ad356fcb45fc2c423bdd21baedb52afd4693e4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 96ad356 Update to 3.52.1