$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-lab-9422-28168/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-lab-9422-28168/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 58b169422327d632c0ee5c698c16e0f80bb81dc8:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         58b169422327d632c0ee5c698c16e0f80bb81dc8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 58b1694 Backport raising VIF limit from 7 to 16 to 25.6.0