$ git clone -n https://src.fedoraproject.org/rpms/jansi1.git /var/lib/mock/f40-build-2172055-51046/root/chroot_tmpdir/scmroot/jansi1
Cloning into '/var/lib/mock/f40-build-2172055-51046/root/chroot_tmpdir/scmroot/jansi1'...
$ git fetch origin 3c593fa0a831f53ded2e90eacd3bb5185f53fb8e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jansi1
 * [new ref]         3c593fa0a831f53ded2e90eacd3bb5185f53fb8e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3c593fa rebuilt w/ no changes