Installing this package via MacPorts at macOS 10.15 fails due to a compilation error. Here is the relevant part of the log:
:info:build Modules/objc/helpers-foundation-nscoder.m:335:37: error: too many arguments to function call, expected 0, have 4 :info:build (void)objc_msgSendSuper(&super, :info:build ~~~~~~~~~~~~~~~~~ ^~~~~~~ :info:build /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/objc/message.h:66:1: note: 'objc_msgSendSuper' declared here
The full build log is attached to the issue. It seems the interface has changed, and the function `objc_msgSendSuper` now takes no arguments. MacPorts ships version 5.2 of pyobjc, but the head of the default branch also seems to be affected. My Xcode version is 11.1.