new install on a catalina system, then run port selfupdate, and then port diagnose:
% sudo port -v diagnose Error: currently installed version of Xcode, 12.1, is not supported by MacPorts. For your currently installed system, only the following versions of Xcode are supported: 11.6 11.5 11.4.1 11.4 11.3.1 11.3 Ken
