diff -ruN bash-4.4.18-orig/configure bash-4.4.18/configure
--- bash-4.4.18-orig/configure	2016-09-07 15:57:01.000000000 -0500
+++ bash-4.4.18/configure	2020-12-07 21:42:11.000000000 -0600
@@ -12806,6 +12806,7 @@
 #endif
 #include <stdio.h>
 #include <ctype.h>
+#include <stdlib.h>
 
 main(c, v)
 int	c;
@@ -12865,6 +12866,7 @@
 
 #include <sys/types.h>
 #include <fcntl.h>
+#include <stdlib.h>
 main()
 {
   int fd1, fd2, fl;
@@ -12916,6 +12918,7 @@
 #ifdef HAVE_UNISTD_H
 #  include <unistd.h>
 #endif
+#include <stdlib.h>
 main()
 {
 # ifdef GETPGRP_VOID
@@ -13129,6 +13132,7 @@
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
+#include <stdlib.h>
 #if !HAVE_DECL_SYS_SIGLIST
 extern char *sys_siglist[];
 #endif
@@ -13210,6 +13214,7 @@
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
+#include <stdlib.h>
 #ifndef UNDER_SYS_SIGLIST_DECLARED
 extern char *_sys_siglist[];
 #endif
@@ -14417,6 +14422,7 @@
 /* end confdefs.h.  */
 #include <sys/types.h>
 #include <signal.h>
+#include <unistd.h>
 int
 main ()
 {
@@ -14458,6 +14464,7 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <fcntl.h>
+#include <stdlib.h>
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif /* HAVE_UNISTD_H */
@@ -14525,6 +14532,8 @@
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
+#include <ulimit.h>
+#include <stdlib.h>
 
 main()
 {
@@ -14584,7 +14593,7 @@
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-
+#include <stdlib.h>
 #ifdef HAVE_UNISTD_H
 #  include <unistd.h>
 #endif
@@ -14651,6 +14660,7 @@
 /* end confdefs.h.  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
@@ -14709,6 +14719,7 @@
 #include <sys/types.h>
 #include <signal.h>
 #include <setjmp.h>
+#include <stdlib.h>
 
 main()
 {
@@ -14775,6 +14786,8 @@
 /* end confdefs.h.  */
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #if defined (HAVE_LOCALE_H)
 #include <locale.h>
 #endif
@@ -14848,6 +14861,7 @@
 /* end confdefs.h.  */
 
 #include <stdio.h>
+#include <stdlib.h>
 
 main()
 {
@@ -15087,6 +15101,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 
 int
 main()
@@ -15133,7 +15148,7 @@
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-
+#include <stdlib.h>
 #include <signal.h>
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
@@ -15219,6 +15234,7 @@
 #include <unistd.h>
 #endif
 #include <signal.h>
+#include <stdlib.h>
 
 /* Add more tests in here as appropriate. */
 main()
@@ -15292,7 +15308,8 @@
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
-
+#include <stdlib.h>
+#include <stdio.h>
 /* Add more tests in here as appropriate. */
 main()
 {
@@ -15531,6 +15548,7 @@
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <sys/types.h>
+#include <stdlib.h>
 int
 main ()
 {
@@ -15602,6 +15620,7 @@
 
 #include <sys/types.h>
 #include <signal.h>
+#include <stdlib.h>
 
 #ifndef NSIG
 #  define NSIG 64