Chai.should() makes Mocha explode
<p>I try to use Chai Should style assertions, but the following statement makes Mocha explode. Here is my complete Require block:</p>

<pre><code>/**                                         
 * Module dependencies.                     
 */                                         
var mongoose = require('mongoose'),         
  User = mongoose.model('User'),            
  moment = require('moment'),               
  SSEvent = mongoose.model('Event'),        
  chai = require('chai');                   

chai.use(require('chai-datetime'));         
var should = chai.should();                   
</code></pre>

<p>Error message:</p>

<pre><code>Running "mochaTest:src" (mochaTest) task
&gt;&gt; Mocha exploded!
&gt;&gt; TypeError: chai.should is not a function
&gt;&gt;     at Object.&lt;anonymous&gt; (/Users/sebastianweikart/Desktop/dev/conftool-nga-mean/modules/events/tests/server/events.server.model.tests.js:13:19)
&gt;&gt;     at Module._compile (module.js:413:34)
&gt;&gt;     at Object.Module._extensions..js (module.js:422:10)
&gt;&gt;     at Module.load (module.js:357:32)
&gt;&gt;     at Function.Module._load (module.js:314:12)
&gt;&gt;     at Module.require (module.js:367:17)
&gt;&gt;     at require (internal/module.js:16:19)
&gt;&gt;     at /Users/sebastianweikart/Desktop/dev/conftool-nga-mean/node_modules/mocha/lib/mocha.js:219:27
</code></pre>

<p>What could possibly be the problem? 
I use 
    <code>"chai": "^3.5.0"</code> and   <code>"mocha": "~2.4.5"</code> which should be the latest stable versions.. </p>

<p>Update:</p>

<p>I now added the following simple stripped down test - and it still explodes:</p>

<pre><code>'use strict';

/**
 * Module dependencies.
 */
var chai = require('chai');
var should = chai.should();



/**
 * Unit tests
 */
describe('Chai Should Test', function () {

  describe('Chai Should() should work', function () {
    it('Chai Should() must work', function (done) {
      var spartacus = 'spartacus';
      should.exist(spartacus);
      done();
    });

  });
});



Running "mochaTest:src" (mochaTest) task
&gt;&gt; Mocha exploded!
&gt;&gt; TypeError: chai.should is not a function
&gt;&gt;     at Object.&lt;anonymous&gt; (/Users/sebastianweikart/Desktop/dev/conftool-nga-mean/modules/events/tests/server/chai.should.test.js:7:19)
</code></pre>