$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-9527-28259/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-9527-28259/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 0ea9a370e72667ee942b5176ffa7bd24fe041d06:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         0ea9a370e72667ee942b5176ffa7bd24fe041d06 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0ea9a37 bump release for test build