what say we just use MacOSX.sdk preferentially on BigSur and up?

[Ryan Schmidt]

On Dec 18, 2020, at 11:44, Joshua Root wrote:

> I don't know if the 11.1 SDK
> actually added new APIs, but if so, building against it will result in
> binaries that may not run on an 11.0 system.

I wouldn't worry about differences between different 11.x SDKs. I don't see this as being different from before. The 10.12.1 (or was it 10.12.2?) SDK, for example, introduced the Touch Bar APIs that had been absent in the original 10.12 SDK. As far as MacPorts goes, I think we should consider any 11.x SDK to be usable, just as before we considered any e.g. 10.12.x SDK to be usable, the only difference is that before all of the e.g. 10.12.x SDKs had the same name, and the 11.x SDKs have different names.

Since Apple doesn't provide a MacOSX11.sdk symlink pointing to the current macOS 11 SDK, we could potentially offer one within the MacPorts prefix, and set the SDK path to that when building. But then something in MacPorts base would have to notice when that symlink breaks and recreate it, e.g. after an Xcode or CLT upgrade, and what to do if Xcode or CLT are upgraded to a future Xcode that doesn't contain the macOS 11 SDK anymore is unclear. So maybe we shouldn't do this.