$ git clone -n https://github.com/xcp-ng-rpms/python /var/lib/mock/v8.3-u-prebuild-9171-27986/root/chroot_tmpdir/scmroot/python
Cloning into '/var/lib/mock/v8.3-u-prebuild-9171-27986/root/chroot_tmpdir/scmroot/python'...
$ git fetch origin 590428057db3dce0f65bf562eaabdb4071ee96d7:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/python
 * [new ref]         590428057db3dce0f65bf562eaabdb4071ee96d7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5904280 bump release for test build