$ git clone -n https://src.fedoraproject.org/rpms/python-optuna.git /var/lib/mock/f42-build-side-1-3502163-45977/root/chroot_tmpdir/scmroot/python-optuna
Cloning into '/var/lib/mock/f42-build-side-1-3502163-45977/root/chroot_tmpdir/scmroot/python-optuna'...
$ git fetch origin 5465faae1e9f44462298e7e7796dbec634b4ace6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-optuna
 * [new ref]         5465faae1e9f44462298e7e7796dbec634b4ace6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5465faa 4.2.1