Information as of October 26, 2020.
The title and the official workaround have been published. Xcode12Workaround.md
--It seems that the cause is that the arm64 architecture overlaps with the actual machine and the simulator with the appearance of Apple Sillicon --It seems that there is a restriction that it can not be used on Apple Sillicon Mac (because it removes the arm64 architecture for the simulator) in the build with this workaround. ――It seems that fundamental measures will be taken soon
It seems that fundamental measures will be taken later, but does the new version change the usage and setting method? I think switching to CocoaPods now is an option.
Well-known SDKs like Firebase haven't officially supported Carthage yet, and it doesn't seem to make much sense to continue Carthage. .. .. (* Firebase Swift Package Manager (SPM) support is also Beta, so SPM is personally It feels a bit premature ...)
By the way, the original issue of this issue is here. https://github.com/Carthage/Carthage/issues/3019