title: Strange errors trying to use haml-coffee with an expressJS app
body: <p>Here is my <code>app.js</code> file following the <a href="https://github.com/netzpirat/haml-coffee#using-with-express" rel="nofollow">haml-coffee guides</a>:</p>
  
  <pre><code>// misc requirements
  var express = require('express')
    , routes = require('./routes')
    , http = require('http')
    , path = require('path');
  
  // setup app
  var app = express();
  
  // set default engine to haml-coffee
  app.engine( 'hamlc', require('haml-coffee'.__express ));
  
  // configure misc stuff
  app.configure(function(){
    app.set('port', process.env.PORT || 3000); // set localhost port to 3000
    app.set('views', __dirname + '/views');    // setup views (templates)
    app.set('view engine', 'hamlc');           // use haml-coffee as default templating engine
    app.set('title', 'Learn Some Code');       // set the website title
  
    app.use(express.favicon());                // favicon handling
    app.use(express.logger('dev'));            // logging
  
    app.use(express.bodyParser());
    app.use(express.methodOverride());
  
    app.use(app.router); // use the router
    app.use(express.static(path.join(__dirname, 'public')));
  });
  
  // only configure this for development
  app.configure('development', function(){
    app.use(express.errorHandler());
  });
  
  app.get('/', routes.index);
  
  http.createServer(app).listen(app.get('port'), function(){
    console.log("Express server listening on port " + app.get('port'));
  });
  </code></pre>
  
  <p>But when I run <code>node app.js</code>... I get this strange error:</p>
  
  <pre><code>module.js:236
    var start = request.substring(0, 2);
                        ^
  TypeError: Cannot call method 'substring' of undefined
      at Function.Module._resolveLookupPaths (module.js:236:23)
      at Function.Module._resolveFilename (module.js:328:31)
      at Function.Module._load (module.js:280:25)
      at Module.require (module.js:362:17)
      at require (module.js:378:17)
      at Object.&lt;anonymous&gt; (/Users/chris/src/learnsomecode/app.js:11:22)
      at Module._compile (module.js:449:26)
      at Object.Module._extensions..js (module.js:467:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:312:12)
  </code></pre>