Using newer SDK on older macOS

[Ryan Carsten Schmidt]

On Dec 3, 2024, at 11:20, Chris Jones via macports-dev wrote:
> 
> It could be the linker version(ld) is also too old in this case. If you are using the system provided one try with a newer one.

You're right. 

I already had the ld64 port installed with its default variant +ld64-274 but that variant is described as the last version without libtapi support so it's not surprising it doesn't work. 

This is the newest variant available. It took me a minute to realize that a newer version is available by *deselecting* the variant it chose for me. That's confusing. With the newer version of ld64 (450.3) installed it's getting further.

It looks like Xcode 8.3 is the first to include a new enough ld, so I'll depend on port:ld64 with earlier Xcode versions and use require_active_variants to ensure none of ld64's variants are selected. Unfortunately this means buildbot won't be able to build the ports so I won't be able to verify that future port updates don't break it.

It would be great if the ld64 port could offer a version that supports libtapi by default on older systems.