$ git clone -n https://github.com/xcp-ng-rpms/xcp-python-libs.git /var/lib/mock/v8.3-incoming-9396-28145/root/chroot_tmpdir/scmroot/xcp-python-libs
Cloning into '/var/lib/mock/v8.3-incoming-9396-28145/root/chroot_tmpdir/scmroot/xcp-python-libs'...
$ git fetch origin b17bb8c1d88aa2a214fe6d63c2c405935e683a89:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xcp-python-libs
 * [new ref]         b17bb8c1d88aa2a214fe6d63c2c405935e683a89 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b17bb8c Merge pull request #6 from xcp-ng-rpms/XS-1555