fix(c): macOS build — bump _POSIX_C_SOURCE so <stdio.h> declares snprintf - #14
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attic/c/glyph-codec/src/stream_validator.c set _POSIX_C_SOURCE to 199309L for clock_gettime/CLOCK_MONOTONIC. On Darwin that lowers __DARWIN_C_LEVEL below 199506L, which hides <stdio.h>'s snprintf declaration; Apple clang then treats the call at line ~691 as an implicit-declaration error and the macOS C job fails to build. Linux glibc does not hide it, so only `C (macos-latest)` failed (`C (ubuntu-latest)` and the prior commit passed before the runner image bumped). 200809L (POSIX.1-2008) still provides clock_gettime and keeps __DARWIN_C_LEVEL >= 199506L, so snprintf is declared on both platforms. Parked port; lib + 14 C tests build/pass on Linux. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Problem
C (macos-latest)fails to build (C (ubuntu-latest)passes):The file already
#include <stdio.h>, but it first does#define _POSIX_C_SOURCE 199309L(forclock_gettime(CLOCK_MONOTONIC)). On Darwin that lowers__DARWIN_C_LEVELbelow199506L, which hidessnprintfin<stdio.h>; Apple clang then errors on the implicit declaration. Linux glibc doesn't hide it, so only the macOS job failed. (Surfaced when the GitHub macOS runner image updated to a stricter Apple clang.)Fix
Bump to
_POSIX_C_SOURCE 200809L(POSIX.1-2008): still providesclock_gettime, and is ≥199506Lsosnprintfis declared on both Linux and macOS. One-line change in the parked C port; no behavior change.Verification
Linux:
make+make testgreen (lib builds, 14/14 C tests pass). macOS fix is the standard Darwin__DARWIN_C_LEVELremedy.🤖 Generated with Claude Code