Fix build on macOS (bug#28571)

* src/conf_post.h (HAVE_FUTIMENS, HAVE_FUTIMESAT, HAVE_UTIMENSAT)
[DARWIN_OS]: Undefine.

diff --git a/src/conf_post.h b/src/conf_post.h
index febdb8b8bf7a0fc940510857e75dcf1d3b46dc49..af946082eecd6cb07cbdb0ddcd699388852474e5 100644 (file)
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -397,3 +397,12 @@ extern int emacs_setenv_TZ (char const *);
 #else
 # define UNINIT /* empty */
 #endif
+
+/* macOS 10.13 supports futimens, futimesat and utimensat, older
+   versions don't but can appear as though they do.  Disable them
+   entirely to avoid breaking cross-version builds on macOS.  */
+#ifdef DARWIN_OS
+# undef HAVE_FUTIMENS
+# undef HAVE_FUTIMESAT
+# undef HAVE_UTIMENSAT
+#endif