$ git clone -n https://github.com/xcp-ng-rpms/libevent.git /var/lib/mock/v8.3-u-pcoval2-10547-29103/root/chroot_tmpdir/scmroot/libevent
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10547-29103/root/chroot_tmpdir/scmroot/libevent'...
$ git fetch origin 2f2dae8902c34a792b2b899be75abd394e04b8c0:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libevent
 * [new ref]         2f2dae8902c34a792b2b899be75abd394e04b8c0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2f2dae8 bump release for test build