$ git clone -n https://github.com/xcp-ng-rpms/ca-certificates /var/lib/mock/v8.3-u-pcoval1-11018-29452/root/chroot_tmpdir/scmroot/ca-certificates
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11018-29452/root/chroot_tmpdir/scmroot/ca-certificates'...
$ git fetch origin d2fc4dc2f01afb73685964baefdc3fffe7988a63:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/ca-certificates
 * [new ref]         d2fc4dc2f01afb73685964baefdc3fffe7988a63 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d2fc4dc bump release for test build