$ git clone -n https://github.com/xcp-ng-rpms/libevent.git /var/lib/mock/v8.3-incoming-9949-28628/root/chroot_tmpdir/scmroot/libevent
Cloning into '/var/lib/mock/v8.3-incoming-9949-28628/root/chroot_tmpdir/scmroot/libevent'...
$ git fetch origin 13a226aa9bad686c06fb578e4cb27766dd4140ff:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libevent
 * [new ref]         13a226aa9bad686c06fb578e4cb27766dd4140ff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 13a226a spec: Disable openssl on upstream el7.src.rpm