$ git clone -n https://github.com/xcp-ng-rpms/ssmtp.git /var/lib/mock/v8.3-incoming-10055-28689/root/chroot_tmpdir/scmroot/ssmtp
Cloning into '/var/lib/mock/v8.3-incoming-10055-28689/root/chroot_tmpdir/scmroot/ssmtp'...
$ git fetch origin b8d47cacc3dcba0e0fbb71e131f881fcfe37abad:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/ssmtp
 * [new ref]         b8d47cacc3dcba0e0fbb71e131f881fcfe37abad -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b8d47ca Update obsolete patch macro with autosetup