Original minimal fix for bug https://bugs.gentoo.org/927734
with it lambdaroo starts compiling
diff -ur MOO-1.8.1.orig/configure.in MOO-1.8.1/configure.in
--- a/configure.in	2024-04-01 07:02:38.948009581 +0000
+++ b/configure.in	2024-04-01 07:04:19.706417934 +0000
@@ -260,7 +260,8 @@
 SAVECC="$CC"
 CC="$CC $opt"
 AC_TEST_PROGRAM([
-int main(int argc, char *argv) { void *ptr; exit(0); }
+#include <stdlib.h>
+int main(int argc, char **argv) { void *ptr; exit(0); }
 ],
 [have_ansi=1
 break],
diff -ur MOO-1.8.1.orig/config.h.in MOO-1.8.1/config.h.in
--- a/config.h.in	2024-04-01 07:11:20.263972630 +0000
+++ b/config.h.in	2024-04-01 07:13:06.909341833 +0000
@@ -253,6 +253,7 @@
  */
 
 #include <limits.h>
+#include <string.h>
 
 #if INT_MAX == 2147483647
    typedef int		int32;
fix for old name of configure.in
--- a/Makefile.in	2024-05-09 05:39:45.019672388 -0000
+++ b/Makefile.in	2024-05-09 05:40:41.162384171 -0000
@@ -69,7 +69,7 @@
 
 DISTFILES = $(SRCS) Makefile.in restart restart.sh \
 	Minimal.db README.Minimal \
-	ChangeLog.txt README configure.in configure config.h.in \
+	ChangeLog.txt README configure.ac configure config.h.in \
 	MOOCodeSequences.txt AddingNewMOOTypes.txt pgperf aclocal.m4
 
 COBJS = $(CSRCS:.c=.o)
@@ -94,7 +94,7 @@
 restart:
 	touch restart
 
-configure: configure.in
+configure: configure.ac
 	# autoconf
 	@echo "Not running autoconf; you must do this by hand."
 	touch configure
QA fixes from Sam, modified for configure.in, as they are applied
before renaming
https://github.com/gentoo/gentoo/pull/36033#issuecomment-2101077890
diff --git a/configure.in b/configure.in
index 685bdfe..24cfe64 100644
--- a/configure.in
+++ b/configure.in
@@ -381,8 +381,10 @@ dnl ***************************************************************************
 echo "checking whether or not fstat() can tell how much data is in a FIFO"
 AC_TEST_PROGRAM([#include <sys/types.h>
 #include <sys/stat.h>
+#include <stdlib.h>
 #include <fcntl.h>
-main()
+#include <unistd.h>
+int main()
 {
 #ifdef NeXT
 /* The NeXT claims to have FIFOs, but using them panics the kernel... */
@@ -407,13 +409,15 @@ AC_TEST_PROGRAM([#include <sys/types.h>
 #include <sys/time.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
 #ifndef FD_ZERO
 #define	NFDBITS		(sizeof(fd_set)*8)
 #define	FD_ZERO(p)	bzero((char *)(p), sizeof(*(p)))
 #define	FD_SET(n, p)	((p)->fds_bits[0] |= (1L<<((n)%NFDBITS)))
 #define	FD_ISSET(n, p)	((p)->fds_bits[0] &  (1L<<((n)%NFDBITS)))
 #endif /* FD_ZERO */
-main()
+int main()
 {
 #ifdef NeXT
 /* The NeXT claims to have FIFOs, but using them panics the kernel... */
@@ -443,7 +447,9 @@ AC_TEST_PROGRAM([#include <sys/types.h>
 #include <poll.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-main()
+#include <stdlib.h>
+#include <unistd.h>
+int main()
 {
   int	rfd, wfd, result; struct pollfd fds[1];
   unlink("/tmp/conftest-fifo");
@@ -461,11 +467,14 @@ main()
 dnl ***************************************************************************
 echo checking whether POSIX-style non-blocking I/O works
 AC_TEST_PROGRAM([#include <sys/types.h>
+#include <sys/stat.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
-handler(int sig) { }
-main ()
+#include <stdlib.h>
+#include <unistd.h>
+void handler(int sig) { return; }
+int main ()
 { /* Testing a POSIX feature, so assume FIFOs */
 #ifdef NeXT
 /* The NeXT claims to have FIFOs, but using them panics the kernel... */