$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-prebuild-9277-28057/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-prebuild-9277-28057/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin d633a56e968013f9a9ab5f652b17643c6c8a462c:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         d633a56e968013f9a9ab5f652b17643c6c8a462c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d633a56 bump release for test build