I had the same problem and did what was mentioned in [Macports ticket #61866] trac.macports.org/ticket/61866) Which was to edit /opt/local/libexec/macports/lib/port1.0/portconfigure.tcl I searched for sdk_version and made the following changes to hard code 11.3.(by this time this was the version of Xcode I had upgraded to to install 11.2) default configure.sdk_version   {11.3} #default configure.sdk_version   {$macosx_sdk_version}      This cleared up the error message. I have no idea if it was a good idea.

I found new to me documentation on how to build a pass for Wallet. It had this detail which looks like what I want to work on. https://developer.apple.com/documentation/walletpasses/pass/nfc?language=objc I need to finish up a pressing project but I will definitely dig into this as my next project. This should work. I can already unlock the my doors with my phone it just runs through a series of keys before it sends a matching key. I think I just need to establish which key belongs to my building so that there are fewer errors or turn off the beep on failure...

The VisionOS certainly responded to the proximity of a laptop. My guess would be if you wanted to integrate with room environment I would look at the iBeacons.