UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.110 Safari/537.36

Steps to reproduce the problem:
1. Enter `var [a] = 2` in the console
2. 
3. 

What is the expected behavior?
You should see a message describing a failed destructuring attempt that would say where exactly the problem lies.

What went wrong?
The error is "undefined is not a function". There's no function involved here so this completely doesn't relate to the actual issue. This is most likely V8 looking for the iterator .next() method & not finding it but that shouldn't surface to the user in this way.

Imagine this in a larger piece of code and you looking for a function that doesn't exist where the problem lies in a different place.

Did this work before? No 

Chrome version: 51.0.2696.0   Channel: canary
OS Version: OS X 10.11.4
Flash Version: Shockwave Flash 21.0 r0

Firefox displays "TypeError: 2 is not iterable".

Safari displays:
"TypeError: [a] is not a function. (In '[a]', '[a]' is undefined)"
In a larger assignment, like:
var [b, [a]] = [2, 3]
you'll see:
TypeError: [a] is not a function. (In '[a]', '[a]' is undefined)
so the place where the problem lies is clear.