FIRAnalyticsConnector: building for Mac Catalyst, but linking in object file built for iOS Simulator
The problem was related to the difference between Firebase/Core and FirebaseCore. The first is a subspec of the Firebase pod that depends on FirebaseAnalytics. The second is only the FirebaseCore pod. Only the latter should be used for macOS.
Solution:For Catalyst, set use FirebaseCore in the PodFile
Update: Here is the PodFile:
platform :ios, '11.0'def reusepodsendtarget 'BatteryCompare' do use_frameworks!# pod 'Firebase/Core' pod 'FirebaseCore' pod 'Firebase/Database' pod 'Firebase/Auth'end