Constants don't exist in process. The same problem is reported follow…

…ing link https://github.com/senchalabs/connect/issues/closed#issue/119

bin/express

@@ -6,7 +6,8 @@
 
 var fs = require('fs')
   , sys = require('sys')
-  , exec = require('child_process').exec;
+  , exec = require('child_process').exec
+  , constants = require('constants');
 
 /**
  * Framework version.
@@ -360,7 +361,7 @@ function createApplicationAt(path) {
 
 function emptyDirectory(path, fn) {
   fs.readdir(path, function(err, files){
-    if (err && err.errno !== process.ENOENT) throw err;
+    if (err && err.errno !== constants.ENOENT) throw err;
     fn(!files || !files.length);
   });
 }