$ git clone -n https://github.com/xcp-ng-rpms/ca-certificates /var/lib/mock/v8.3-u-pcoval1-11067-29504/root/chroot_tmpdir/scmroot/ca-certificates
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11067-29504/root/chroot_tmpdir/scmroot/ca-certificates'...
$ git fetch origin 5bf31c41e016b83311cb5f42f16e189f1fe82baf:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/ca-certificates
 * [new ref]         5bf31c41e016b83311cb5f42f16e189f1fe82baf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5bf31c4 bump release for test build