--- configure.orig	2021-03-25 19:36:48.000000000 -0700
+++ configure	2021-03-25 19:43:01.000000000 -0700
@@ -3419,6 +3419,7 @@
 #include "confdefs.h"
 
 #include <term.h>
+#include <stdlib.h>
 
 int main (void)
 {
@@ -3551,6 +3552,7 @@
 #line 3552 "configure"
 #include "confdefs.h"
 #include <ctype.h>
+#include <stdlib.h>
 #define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
 #define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
 #define XOR(e, f) (((e) && !(f)) || (!(e) && (f)))
@@ -4394,6 +4396,8 @@
  */
 #include <stdio.h>
 #include <sys/types.h>
+#include <stdlib.h>
+#include <unistd.h>
 
 int     pid;
 int     pg1, pg2, pg3, pg4;
@@ -4477,6 +4481,7 @@
 
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <stdlib.h>
 int main (void)
 {
 #ifndef SO_SNDLOWAT
@@ -4560,6 +4565,7 @@
 #include <sys/signal.h>
 #include <signal.h>
 #include <unistd.h>
+#include <stdlib.h>
 int main(void)
 {
 	char *s = sys_siglist[0];
@@ -4644,6 +4650,7 @@
 #include "confdefs.h"
 #include <stdio.h>
 #include <sys/types.h>
+#include <stdlib.h>
 int main(void)
 {
   FILE *f=fopen("conftestval", "w");
@@ -4692,6 +4699,7 @@
 #include "confdefs.h"
 #include <stdio.h>
 #include <sys/types.h>
+#include <stdlib.h>
 int main(void)
 {
   FILE *f=fopen("conftestval", "w");
@@ -4738,6 +4746,7 @@
 #include "confdefs.h"
 #include <stdio.h>
 #include <sys/types.h>
+#include <stdlib.h>
 int main(void)
 {
   FILE *f=fopen("conftestval", "w");
@@ -4790,6 +4799,7 @@
 
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <stdlib.h>
 int main(void)
 {
 	struct sockaddr sa;
@@ -4918,6 +4928,7 @@
 #include <netdb.h>
 #include <sys/un.h>
 #include <stdlib.h>
+#include <string.h>
 
 int main(void)
 {