$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn2-8829-27774/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn2-8829-27774/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 235d07da648afd4efe6789bbba896036b03a80c3:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         235d07da648afd4efe6789bbba896036b03a80c3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 235d07d bump release for test build