--- dist/configure.orig	2013-09-10 01:35:02.000000000 +1000
+++ dist/configure	2021-02-02 22:31:20.000000000 +1100
@@ -21275,7 +21275,7 @@
 		static lwp_cond_t ci = SHAREDCV;
 		lwp_mutex_t mutex = mi;
 		lwp_cond_t cond = ci;
-		exit (
+		return (
 		_lwp_mutex_lock(&mutex) ||
 		_lwp_mutex_unlock(&mutex));
 
@@ -21305,7 +21305,7 @@
 		mutex_t mutex;
 		cond_t cond;
 		int type = USYNC_PROCESS;
-		exit (
+		return (
 		mutex_init(&mutex, type, NULL) ||
 		cond_init(&cond, type, NULL) ||
 		mutex_lock(&mutex) ||
@@ -21335,7 +21335,7 @@
 		mutex_t mutex;
 		cond_t cond;
 		int type = USYNC_PROCESS;
-		exit (
+		return (
 		mutex_init(&mutex, type, NULL) ||
 		cond_init(&cond, type, NULL) ||
 		mutex_lock(&mutex) ||
@@ -21370,7 +21370,7 @@
 {
 
 	#if (defined(i386) || defined(__i386__)) && defined(__GNUC__)
-		exit(0);
+		return (0);
 	#else
 		FAIL TO COMPILE/LINK
 	#endif
@@ -21393,7 +21393,7 @@
 {
 
 	#if (defined(x86_64) || defined(__x86_64__)) && defined(__GNUC__)
-		exit(0);
+		return (0);
 	#else
 		FAIL TO COMPILE/LINK
 	#endif
@@ -21445,7 +21445,7 @@
 
 	#if defined(__sparc__) && defined(__GNUC__)
 		asm volatile ("membar #StoreStore|#StoreLoad|#LoadStore");
-		exit(0);
+		return (0);
 	#else
 		FAIL TO COMPILE/LINK
 	#endif
@@ -21516,7 +21516,7 @@
 	msem_init(&x, 0);
 	msem_lock(&x, 0);
 	msem_unlock(&x, 0);
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21548,7 +21548,7 @@
 	msem_init(&x, 0);
 	msem_lock(&x, 0);
 	msem_unlock(&x, 0);
-	exit(0);
+	return (0);
 
   ;
   return 0;
@@ -21600,7 +21600,7 @@
 {
 
 #if defined(__USLC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21731,7 +21731,7 @@
 {
 
 #if defined(__alpha) && defined(__DECC)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21756,7 +21756,7 @@
 {
 
 #if defined(__alpha) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21781,7 +21781,7 @@
 {
 
 #if defined(__arm__) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21806,7 +21806,7 @@
 {
 
 #if (defined(__mips) || defined(__mips__)) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21831,7 +21831,7 @@
 {
 
 #if (defined(__hppa) || defined(__hppa__)) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21856,7 +21856,7 @@
 {
 
 #if (defined(__powerpc__) || defined(__ppc__)) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21881,7 +21881,7 @@
 {
 
 #if (defined(mc68020) || defined(sun3)) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21906,7 +21906,7 @@
 {
 
 #if defined(__MVS__) && defined(__IBMC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21931,7 +21931,7 @@
 {
 
 #if defined(__s390__) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21956,7 +21956,7 @@
 {
 
 #if defined(__ia64) && defined(__GNUC__)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -21981,7 +21981,7 @@
 {
 
 #if defined(_UTS)
-	exit(0);
+	return (0);
 #else
 	FAIL TO COMPILE/LINK
 #endif
@@ -22464,9 +22464,9 @@
 {
 
 	#if ((defined(i386) || defined(__i386__)) && defined(__GNUC__))
-		exit(0);
+		return (0);
 	#elif ((defined(x86_64) || defined(__x86_64__)) && defined(__GNUC__))
-		exit(0);
+		return (0);
 	#else
 		FAIL TO COMPILE/LINK
 	#endif
@@ -22491,7 +22491,7 @@
 {
 
 	volatile unsigned val = 1;
-	exit (atomic_inc_uint_nv(&val) != 2 ||
+	return (atomic_inc_uint_nv(&val) != 2 ||
 	      atomic_dec_uint_nv(&val) != 1 ||
 	      atomic_cas_32(&val, 1, 3) != 3);
 
@@ -24192,6 +24192,11 @@
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
+#include <stdio.h>
+#if HAVE_STRING_H
+#include <string.h>
+#endif
+
 int
 main ()
 {
@@ -24226,7 +24231,12 @@
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-		main() {
+#include <stdio.h>
+#if HAVE_STRING_H
+#include <string.h>
+#endif
+
+		int main() {
 			$db_cv_seq_type l;
 			unsigned $db_cv_seq_type u;
 			char buf[100];
@@ -24309,6 +24319,9 @@
     #include <fcntl.h>
     #include <sys/mman.h>
     #include <signal.h>
+    #if HAVE_UNISTD_H
+    #include <unistd.h>
+    #endif
 
     #define TEST_MMAP_BUFSIZE	(16 * 1024)
     #define TEST_MMAP_EXTENDSIZE	(16 * 1024 * 1024)
@@ -24319,10 +24332,10 @@
     int catch_sig(sig)
 	    int sig;
     {
-	    exit(1);
+	    return (1);
     }
 
-    main() {
+    int main() {
 	    const char *underlying;
 	    unsigned gapsize;
 	    char *base;