--- config/config.h.orig	2026-08-08 21:56:03.608885211 +0000
+++ config/config.h	2026-08-08 21:56:22.499353679 +0000
@@ -241,3 +241,12 @@
 
 /* Define for large files, on AIX-style hosts. */
 /* #undef _LARGE_FILES */
+
+/* The defines above describe a Linux/glibc host; fix up the handful of
+   them which do not hold on Darwin. */
+#ifdef __APPLE__
+/* <byteswap.h> is a glibc header. */
+#undef HAVE_BYTESWAP_H
+/* posix_fallocate() is not implemented on Darwin. */
+#undef HAVE_POSIX_FALLOCATE
+#endif /* __APPLE__ */