What actually happens: The best I have managed to do is to get Cocoapods to install SwiftAA for iOS and watchOS, and the code runs on both platforms, including in unit tests. (And it correctly calculates Moon phases, there, too.) However, the macOS (specifically, Mac Catalyst) version of SwiftAA fails to build. Attempting to use it on macOS results in a message of "No such module ‘SwiftAA’” in code. On disk (see picture), it is clear that Xcode has built iOS and watchOS versions of SwiftAA and a related framework it depends on, ObjCAA, but it never builds them for Mac Catalyst.
Environment: I am programming in Xcode 12.5.1 on my M1 MacBook Pro running macOS Big Sur 11.5.2. Cocoapods is 1.10.2.
SwiftAA: I am working with version 2.3.0.
I feel very confused in that there seems to be nothing in my project that indicates that iOS and Mac Catalyst should be treated any differently, but clearly that is what Xcode is doing. Does anyone have any idea what might be possibly going wrong and how to fix it? Thanks in advance.