Force Xcode SDK instead of CLI SDK?

[Clemens Lang]

Hi Josh,

On Sat, Nov 21, 2020 at 01:47:31AM +1100, Joshua Root wrote:
> On 2020-11-21 01:20 , Aaron Madlon-Kay wrote:
> > Seems reasonable to me.
> 
> Unfortunately it isn't really. The result of not using an SDK matching
> your OS version is that autoconf (and cmake etc.) detects functions
> that aren't available at runtime, causing crashes because checking for
> weak-linked symbols is very uncommon in the world outside of
> Mac-centric developers.

I'm very-well aware of this problem. However, when `use_xcode` is set, I
think we must prefer an Xcode SDK with the required tools for GUI stuff,
even if it isn't the exact version and a CLT SDK with the expected
version is available.

Especially for the cases where `use_xcode` is required I would expect
that the software is aware how macOS SDKs work and the pitfalls w.r.t.
autoconf usage.

-- 
Clemens