Sandbox issues with Swift Package Manager

[Andrew Udvare]

> On 2021-12-10, at 13:01, Mark Anderson <mark at macports.org> wrote:
> 
> SPM and Workspace builds need to be added to the XCode portgroup - it's something that I've been working on for a while.
> 
> I'm a little surprised the sandbox is involved at all. Is it XCode's sandbox complaining? Or is it Terminal? Make sure the terminal has full disk access.

This is sandbox-exec(1) complaining. When I run the same xcodebuild command without MacPorts the build works fine in the same terminal.

https://github.com/macports/macports-base/blob/master/src/port1.0/portsandbox.tcl