$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-abourgeois1-9567-28312/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-abourgeois1-9567-28312/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 38fbfa412d941fbbb9f5e7ed56c27c9942f10829:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         38fbfa412d941fbbb9f5e7ed56c27c9942f10829 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 38fbfa4 bump release for test build