$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-9986-28650/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-9986-28650/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 9f96cc54f68e448e8e623da7a28a7c4a85464d60:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         9f96cc54f68e448e8e623da7a28a7c4a85464d60 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9f96cc5 bump release for test build