Function onerror

packages/react-error-overlay/fixtures/bundle_u.mjs:5239–5245

(err)

      }
    };
    var onerror = function(err) {
      debug('onerror', err);
      if (iframe) {
        cleanup();
        errorCallback(err);
      }
    };
    var post = function(msg, origin) {
      debug('post', msg, origin);
      try {