$ git clone -n https://src.fedoraproject.org/forks/hypersa/rpms/ghc-x509-system.git /var/lib/mock/f39-build-2208466-52135/root/chroot_tmpdir/scmroot/ghc-x509-system
Cloning into '/var/lib/mock/f39-build-2208466-52135/root/chroot_tmpdir/scmroot/ghc-x509-system'...
$ git fetch origin 2c8cc4cc45c325662fb2f128a333388c1ea95bce:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/hypersa/rpms/ghc-x509-system
 * [new ref]         2c8cc4cc45c325662fb2f128a333388c1ea95bce -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2c8cc4c rv64 rebuild