$ git clone -n https://github.com/xcp-ng-rpms/openssh.git /var/lib/mock/v8.3-incoming-10969-29394/root/chroot_tmpdir/scmroot/openssh
Cloning into '/var/lib/mock/v8.3-incoming-10969-29394/root/chroot_tmpdir/scmroot/openssh'...
$ git fetch origin a6d671bc47baf6e5d3f044101e336b43dd755e0d:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/openssh
 * [new ref]         a6d671bc47baf6e5d3f044101e336b43dd755e0d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a6d671b Add related announcement