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

On Tue, Mar 30, 2021 at 7:39 PM James Hilliard
<james(dot)hilliard1(at)gmail(dot)com> wrote:
> On Mon, Mar 29, 2021 at 11:58 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > We haven't claimed in the past to support MACOSX_DEPLOYMENT_TARGET,
> > and I'm not sure we should start now. How many people actually care
> > about that?
>
> Seems kinda important for anyone who wants to build postgres
> compatible with targets older than the host system.

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.

I suppose an alternative strategy would be to try to detect the
mismatch and spit out a friendlier warning, if we decide we're not
going to support such builds.