> Is it really necessary ?

There is a bug, and this is one fix, so...something is necessary yes.

> IMHO it's awful

Sorry :(

> and potentially error prone.

I don't think so? Cyclic references are ok unless you're trying to serialize Marionette as JSON.

> why not add a reference on Marionette, like Marionette.history ?

I disliked the idea of cloning over the object without changing it. My primary concern there was that people might be confused into thinking that Marionette's history is different than Backbone's.

It's just a matter of preference. Both are pretty ugly...I agree. But I'm not persuaded that one is less awful than the other atm.