Re: BUG #16737: error running compiled C program with connection to Postgres

PG Bug reporting form <noreply@postgresql.org> writes:
> when running a compiled C program with connection attributes to postgres, I
> now get the following error after upgrading to Big Sur:

> dyld: Library not loaded: /usr/lib/libpq.5.dylib 
> Referenced from: /xxdir/program
>   Reason: image not found
> Abort trap: 6

Complaining here won't help you with that.  The Postgres project has
no say in what Apple chooses to include in their operating system.

Having said that, the version that Apple was shipping up through
Catalina was pretty darn obsolete:

$ ls -1 /usr/lib/libpq*
/usr/lib/libpq.5.6.dylib
/usr/lib/libpq.5.dylib
/usr/lib/libpq.dylib

libpq.5.6 would be from Postgres 9.3, which has been out of support
for some time ... and it'd be a very good bet that this wasn't an
end-of-life version anyway, meaning it's certainly missing security
and other bug fixes.  So personally I wouldn't use that anyway.

The most obvious path forward is to use Homebrew or MacPorts to
install Postgres, as well as anything else you need.  (It looks
like Apple culled a heck of a lot from /usr/lib in Big Sur,
not only libpq.)

            regards, tom lane