$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-incoming-11326-29646/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-incoming-11326-29646/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 21bf5b917e2fea58d9d154415a6fed7af4680dcf:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         21bf5b917e2fea58d9d154415a6fed7af4680dcf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21bf5b9 Merge pull request #124 from xcp-ng-rpms/asv/fix-snap-export-qcow2