express middleware rendering bug?

example.js

var express = require('express');
app.use(function(req, res, next) {
  if (req.url === '/login') {
    req.app.set('views', __dirname + '/views');
    req.app.set('view engine', 'jade');
    res.render('login');
  }
  next();
});

app.get('/', function(req, res) {
  res.send('hi');
});

app.listen(3000);

// runtime
± DEBUG=express:* node test.js
  express:application compile etag weak +0ms
  express:application compile trust proxy false +1ms
  express:application booting in development mode +2ms
  express:router:layer new  +0ms
  express:router use / query +0ms
  express:router:layer new  +0ms
  express:router use / expressInit +1ms
  express:router:layer new  +0ms
  express:router use / anonymous +0ms
  express:router:route new / +0ms
  express:router:layer new / +0ms
  express:router:route get / +0ms
  express:router dispatching GET /login +5s
  express:router query  : /login +2ms
  express:router expressInit  : /login +1ms
  express:router anonymous  : /login +0ms
  express:application default 404 +374ms
  express:application default 404 +0ms
Error: Can't set headers after they are sent.
    at ServerResponse.OutgoingMessage.setHeader (http.js:689:11)
    at /Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/application.js:157:9
    at /Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/router/index.js:140:5
    at /Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/router/index.js:267:10
    at next (/Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/router/index.js:165:14)
    at next (/Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/router/index.js:182:38)
    at Layer.handle (/Users/rdegges/Dropbox/Code/stormpath/stormpath-express/test.js:18:3)
    at trim_prefix (/Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/router/index.js:254:17)
    at /Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/router/index.js:216:9
    at Function.proto.process_params (/Users/rdegges/Dropbox/Code/stormpath/stormpath-express/node_modules/express/lib/router/index.js:286:12)