Framework was built with Xcode 13 RC and built in swift version of 5.5 The app which is integrating the framework is using Xcode 12 RC with 5.3 swift version. Yes this looks like downward copability issue. Any clues?

I looked at spindump file which got generated when tests failed to execute. It mentioned something about a pod SDK which I have added as a dependency (hard to read but just go through the names of your frameworks and check if you find any resembling one). It needed an updated version for it. I suggest update dependent frameworks/pods etc.

I looked at spindump file which got generated when tests failed to execute. It mentioned something about a pod SDK which was added as dependency. It needed an updated version. I suggest update dependent frameworks.