Firebase Undefined symbols for architecture x86_64

Question

I am using firebase as part of a project I am working on in iOS, and I just stumbled upon the following linking error when I try to compile my code against an iPhone 6 or 7

Answer 1

If nothing is working for you then try downgrading firebase pods. I downgraded it to '6.27.0' and it worked like a charm. I read this solution here.

pod 'Firebase/Core', '6.27.0'