When RollbackImpl::runRollback() exits, we log a rollback summary by calling RollbackImpl::_summarizeRollback() within an ON_BLOCK_EXIT scope guard. This method calls OplogInterfaceRemote::toString(), which can throw if the remote host is unreachable. The uncaught exception then triggers a std::terminate.

The failure manifests as a hang when running rollback_with_socket_error_then_steady_state.js in the replica_sets_auth suite.