Sinon.stub(obj, method) takes 1.5 seconds to run in meteor

[savv]

I noticed that one of my tests takes 1.5 seconds to execute. I've narrowed the cause down to the following snippet:

describe('SomeApi', function() {
it('gets events', function() {
var startMs = new Date();
var a = {list: function(){}};
sinon.stub(a, 'list');
console.log('meteor-sinon-wtf', new Date() - startMs);
});
});
this prints: meteor-sinon-wtf 1441

if I refresh the test runner, it prints 1.

If I put this in two consecutive tests, then it prints (on the first execution):
meteor-sinon-wtf 1403
meteor-sinon-wtf 0

Finally, if I call sinon.stub() (without stubbing an object's method) it again only takes <1ms.

It seems to be related to the first execution only. If I run the same command in pure node, it doesn't happen. So it seems to be something specific to Meteor. I'm using practicalmeteor:mocha and I'm importing sinon from practicalmeteor:sinon.

[DominikGuzei]

same here

[romulobr]

I have the same issue, but I'm not using meteor at all, just a combination of webpack, node, mocha, sinon and jsdom. Please let me know if you find an answer...