assert.deepEqual / expect().to.deep.equal incorrect with Symbols as keys

[derMart]

consider this:

var sym = Symbol('foo');
expect({[sym] : 1}).to.deep.equal({[sym] : 0});
assert.deepEqual({[sym] : 1}, {[sym] : 0});

I would expect both variants to fail, but they pass and do not throw an Error.
Using chai 4.2.0

The documentation does not state anything about this behaviour.
Is this working as intended or a bug?

[snewcomer]

Seeing this as well. Going to dig around and see if I can make a PR...

[snewcomer]

This PR has been merged - chaijs/deep-eql#83

Awaiting a bump on deep-eql then we can work on this PR - #1458!

cc @keithamus