$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-incoming-9502-28236/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-incoming-9502-28236/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 9b799abda1eb6ebef8442e3d6ce62b071ce31e3d:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         9b799abda1eb6ebef8442e3d6ce62b071ce31e3d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9b799ab  Revert rsyslog changes from Xenserver (#112)