From b1508ade39ee91a157018e61935d3994d6049391 Mon Sep 17 00:00:00 2001
From: Mikael Djurfeldt <djurfeldt@nada.kth.se>
Date: Wed, 15 Sep 1999 15:22:07 +0000
Subject: [PATCH] * backtrace.c: #include <unistd.h> if present.

---
 libguile/backtrace.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libguile/backtrace.c b/libguile/backtrace.c
index 691b8a09d..620252eb0 100644
--- a/libguile/backtrace.c
+++ b/libguile/backtrace.c
@@ -46,6 +46,10 @@
 #include <stdio.h>
 #include <ctype.h>
 
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
 #include "_scm.h"
 #include "stacks.h"
 #include "srcprop.h"
-- 
2.20.1