$ git clone -n https://src.fedoraproject.org/rpms/xeus-zmq.git /var/lib/mock/f39-build-1602497-38571/root/chroot_tmpdir/scmroot/xeus-zmq
Cloning into '/var/lib/mock/f39-build-1602497-38571/root/chroot_tmpdir/scmroot/xeus-zmq'...
$ git fetch origin 37cec20f33f4c2fd18b3d8144f773e3e89e4dbe1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xeus-zmq
 * [new ref]         37cec20f33f4c2fd18b3d8144f773e3e89e4dbe1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 37cec20 Initial import BZ 2242660