What would happen if you renounced your citizenship in one country while in another one without a visa?

Question

Just wondering, because you would be stateless and be a illegal immigrant.

Answer the question what would happen with these examples?

Example US and Canada then Canada and US

Australia and US then US and Australia

Canada and Australia or Australia and Canada

Answer 1

IDK, but that sounds like the idea of a moron.

Answer 2

I have no idea, it sounds risky

Answer 3

the US or Australia would boot you out immediately.