$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-9555-28302/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-9555-28302/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 8e7664c75412025726e91f34b57990f11ff37dff:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         8e7664c75412025726e91f34b57990f11ff37dff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8e7664c bump release for test build