Looks like Cocoapods and XCode12 are throwing lot of issues that are difficult to manage. In XCode12, it prompted me to perform a settings update of project to update deployment target of all pods to iOS 12 and I did it. But immediately after updating settings, I get these errors in nanopb-umbrella.h:
There are also pod warnings such as:
The iOS deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.0.99.
I thought upgrading project settings that updates deployment target of each pod to iOS 12.0 will fix it but instead it causes build errors. Pod update doesn't help either. Neither does pod deintegrate and reinstall along with removing DerivedData.
A fix is at CocoaPods/CocoaPods#9905 and targeted for CocoaPods 1.10. As a (temporary) workaround you can set "Quoted include in framework headers" in pods project build settings to NO.