For those affected by this regression, check out monkeydom/TCMPortMapper on GitHub. TCMPortMapper is pretty ancient but still works pretty well.

DNSServiceNATPortMappingCreate is still broken on macOS 12.0.1, which shows that either Apple doesn't care or lied about fixing this while they just wanted to remove that API. Luckily I was able to find an alternative so my users (which are Apple's as well to an extent) don't end up with a broken service. If you want to retire the API, just say so.

Is DNSServiceNATPortMappingCreate now only available for sandboxed apps? If I enable Sandbox in the test project I included with the radar, DNSServiceNATPortMappingCreate returns kDNSServiceErr_NoError. Port mapping still fails of course but if I disable Sandbox, I get this error: DNSCreate[30499:361087] dnssd_clientstub ConnectToServer: connect() failed path:/var/run/mDNSResponder Socket:3 Err:-1 Errno:1 Operation not permitted Unfortunately since it seems like this won't be addressed until GM ships (still not fixed in macOS 12 Beta 7), I have no way to know for sure if this is just a bug or a new requirement. And because of that, I have no way to prepare for this and it may be too late when GM ships. That is if this issue is resolved then. Not cool. Not cool at all.