$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-10314-28883/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-10314-28883/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin f9b3e12becd3f6769ac0f5b57ad0353692e66525:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         f9b3e12becd3f6769ac0f5b57ad0353692e66525 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f9b3e12 bump release for test build