$ git clone -n https://github.com/xcp-ng-rpms/libevent /var/lib/mock/v8.3-incoming-9881-28597/root/chroot_tmpdir/scmroot/libevent
Cloning into '/var/lib/mock/v8.3-incoming-9881-28597/root/chroot_tmpdir/scmroot/libevent'...
$ git fetch origin acad784b6db893360ac83db91b6d2566a85506da:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libevent
 * [new ref]         acad784b6db893360ac83db91b6d2566a85506da -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at acad784 spec: Disable openssl on upstream el7.src.rpm