message: Stop trying to `require` the backend in frontend devServer.
  This is another big breaking change that apps will need to react to!
diff: @@ -83,9 +83,6 @@ module.exports = function(proxy, allowedHost) {
  before(app) {
  // This lets us open files from the runtime error overlay.
  app.use(errorOverlayMiddleware());
  -
  - global.webpackDevServer = app;
  - require(paths.appBuiltMainJs);
  },
  };
  };
  