$ git clone -n https://github.com/xcp-ng-rpms/xapi /var/lib/mock/v8.3-u-psafont2-10236-28810/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-psafont2-10236-28810/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin a4f2e497bb197ea4bac4ca41422da3021cb97d2d:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         a4f2e497bb197ea4bac4ca41422da3021cb97d2d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a4f2e49 bump release for test build