Jianghua Yang <yjhjstz@gmail.com> writes:
> Include <xlocale.h> explicitly on Apple platforms. This header
> declares nl_langinfo_l() unconditionally and is the standard way
> to access locale-specific extensions on macOS.
What version are you testing? v18 and HEAD already unconditionally
include <xlocale.h> in our c.h (around line 80 in HEAD), and older
branches don't use nl_langinfo_l().
See also [1].
regards, tom lane
[1] https://www.postgresql.org/message-id/1026321.1765562828%40sss.pgh.pa.us