Is isysroot useful for non-universal?

[Anders F Björklund]

Toby Peterson wrote:

> Ultimately the solution to this should be to simply stop building
> against an SDK.
>
> Nothing fundamentally wrong with building against an SDK, but it
> shouldn't be tied to universal building, nor should it be the default
> behavior.

The +universal "variant" is a glorious mess that mixes all
of fatness (universalness, archness, whatever...) and
MDT and SDK together in one big undefined configuration.

Back then in the day, ppc+i386/10.4/MacOSX10.4u.sdk seemed
like a reasonable default for building "Universal Binaries".
These days, i686+x86_64/10.5/MacOSX10.5.sdk is more popular*.

There's some minimal separation into archs/target/sysroot,
but it's still all covered with the "universal" variant -
just like flags are covered with the "configure" target.

Despite the fact that they cover much more than "just"
universal (arch) and configure (autotools), that is...
So it's more of a legacy quirk, than a design decision.

--anders

* yes, I know that excludes PowerPC and Tiger users.