Unfortunately, this is not the only build system in this repo... (far from it).

So modifying endian.h would be preferred.

Can we move both defines to endian.h?

Can we move both defines to endian.h?

I'd really appreciate that since when I just add the define in endian.h it still fails when building query.c and I haven't tracked down the inclusion chain yet (where endian.h seems to be included some other way, perhaps via time.h or another system header).

Probably because by default, the Makefile compiles each C file individually, so you'd have to define this in every source file that needs it. Would adding #undef _POSIX_C_SOURCE work for NetBSD?

I pushed a different version that I think follows your suggestions. I think it's ugly, but it works.

Yeah, that's a little ugly but I guess it's fine. I'm a little confused though, because lexer.c also includes endian.h (through unicode.h) - does the library build just fine on NetBSD as this PR is? Also, if you could add a short comment above the NetBSD undef in query.c explaining why that's there, that'd be great

I've added a comment about the #undef.
Yes, the git head of my fork builds without warnings on NetBSD.
lexer.c has fewer includes than query.c, I guess that's the reason.

Might have wanted to squash that...

Successfully created backport PR for release-0.25:

• build: do not define _POSIX_C_SOURCE on NetBSD #4196