strchrnul added in 15.4

[David Gilman]

Note that macOS 15.4 added strchrnul to the C standard library. It's
behind the MACOSX_DEPLOYMENT_TARGET of 15.4 or greater, however, in at
least some cases a configure script could find strchrnul only to have
failures at build time when MACOSX_DEPLOYMENT_TARGET is defined. If
there are any ports, or the builders/the port system itself is
definining MACOSX_DEPLOYMENT_TARGET to 15.0 they are at risk of
tripping this when building on 15.4.

This happened in PostgreSQL, there is a patch to their configure.ac
and a discussion here.
https://www.postgresql.org/message-id/flat/E1tziZ6-002AW9-2C%40gemulon.postgresql.org
I can fix the issue in the PostgreSQL ports in MacPorts but giving you
all a notice if you see it elsewhere.

-- 
David Gilman
:DG<