Re: [PATCH v3 1/1] Fix detection of preadv/pwritev support for OSX.

Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:
> Personally I'm mostly concerned about making it easy for new
> contributors to get a working dev system going on a super common
> platform without dealing with hard-to-diagnose errors, than people who
> actually want a different target as a deliberate choice. Do I
> understand correctly that there a period of time each year when major
> upgrades come out of sync and lots of people finish up running a
> toolchain and OS with this problem for a while due to the default
> target not matching? If so I wonder if other projects are running
> into this with AC_REPLACE_FUNCS and what they're doing.

Yeah, we've seen this happen at least a couple of times, though
it was only during this past cycle that we (I anyway) entirely
understood what was happening.

The patches we committed in January (4823621db, 9d23c15a0, 50bebc1ae)
to improve our PG_SYSROOT selection heuristics should theoretically
improve the situation ... though I admit I won't have a lot of
confidence in them till we've been through a couple more rounds of
asynchronous-XCode-and-macOS releases. Still, I feel that we
ought to leave that code alone until we see how it does.

regards, tom lane