From 672ab3b583a888f5aebdadda1335248c09d83841 Mon Sep 17 00:00:00 2001
From: Shokunin <30949000+tetrisgm@users.noreply.github.com>
Date: Thu, 8 Oct 2026 00:02:45 -0700
Subject: [PATCH] Host sampler: include <sys/ucontext.h> on macOS

<ucontext.h> stops with #error unless _XOPEN_SOURCE is defined, so
debug-tools runtime builds on macOS failed at host_sampler.c. The
sampler only needs ucontext_t's machine context, which
<sys/ucontext.h> declares without the deprecated routines.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 runtime/src/host_sampler.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/runtime/src/host_sampler.c b/runtime/src/host_sampler.c
index e91919b2..5b1e891b 100644
--- a/runtime/src/host_sampler.c
+++ b/runtime/src/host_sampler.c
@@ -107,7 +107,11 @@ void host_sampler_start(void) {
 #elif defined(__linux__) || defined(__APPLE__)
 #include <signal.h>
 #include <sys/time.h>
+#if defined(__APPLE__)
+#include <sys/ucontext.h>   /* <ucontext.h> errors without _XOPEN_SOURCE */
+#else
 #include <ucontext.h>
+#endif
 #include <pthread.h>
 #include <dlfcn.h>