$ git clone -n https://github.com/xcp-ng-rpms/ca-certificates /var/lib/mock/v8.3-u-pcoval2-11059-29494/root/chroot_tmpdir/scmroot/ca-certificates
Cloning into '/var/lib/mock/v8.3-u-pcoval2-11059-29494/root/chroot_tmpdir/scmroot/ca-certificates'...
$ git fetch origin 11d8fd22c7a9e265f7632f76869286e2c55071ce:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/ca-certificates
 * [new ref]         11d8fd22c7a9e265f7632f76869286e2c55071ce -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 11d8fd2 bump release for test build