$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-9833-28548/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-9833-28548/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 3f3074dcecc26cd1c8b56617a05bdaf64c31c281:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         3f3074dcecc26cd1c8b56617a05bdaf64c31c281 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3f3074d bump release for test build