diff -Nurd xemacs-21.5.35.orig/Makefile.in.in xemacs-21.5.35/Makefile.in.in
--- xemacs-21.5.35.orig/Makefile.in.in	2023-05-13 14:09:51.000000000 -0400
+++ xemacs-21.5.35/Makefile.in.in	2024-03-12 01:34:59.000000000 -0400
@@ -137,7 +137,7 @@
 libdir=@libdir@
 
 ## Where to install XEmacs's man pages, and what extension they should have.
-mandir=@mandir@
+mandir=@mandir@/man1
 manext=.1
 
 ## Where to install and expect the info files describing XEmacs.  In the
diff -Nurd xemacs-21.5.35.orig/configure xemacs-21.5.35/configure
--- xemacs-21.5.35.orig/configure	2023-05-13 14:09:51.000000000 -0400
+++ xemacs-21.5.35/configure	2024-03-12 01:44:38.000000000 -0400
@@ -16992,7 +16992,6 @@
 else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#define XPM_NUMBERS
 #include <X11/xpm.h>
     int main(int c, char **v) {
     return c == 1 ? 0 :
@@ -17521,6 +17520,7 @@
 else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
+#include <string.h>
 #include <png.h>
     int main(int c, char **v) {
     if (c == 1) return 0;
@@ -20259,6 +20259,8 @@
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
+#include <stdlib.h>
+#include <string.h>
 #if defined (__CYGWIN__)
 #include <alloca.h>
 #elif defined (__GNUC__)
diff -Nurd xemacs-21.5.35.orig/lwlib/Makefile.in.in xemacs-21.5.35/lwlib/Makefile.in.in
--- xemacs-21.5.35.orig/lwlib/Makefile.in.in	2023-05-13 14:09:53.000000000 -0400
+++ xemacs-21.5.35/lwlib/Makefile.in.in	2024-03-11 22:43:18.000000000 -0400
@@ -56,7 +56,7 @@
 
 c_switch_all=@c_switch_all@
 
-cppflags = $(CPPFLAGS) -I. -I$(srcdir)/../src $(c_switch_all)
+cppflags = -I. -I$(srcdir)/../src $(CPPFLAGS) $(c_switch_all)
 cflags = $(CFLAGS) $(cppflags)
 
 #ifdef SOLARIS2
diff -Nurd xemacs-21.5.35.orig/src/Makefile.in.in xemacs-21.5.35/src/Makefile.in.in
--- xemacs-21.5.35.orig/src/Makefile.in.in	2023-05-13 14:09:53.000000000 -0400
+++ xemacs-21.5.35/src/Makefile.in.in	2024-03-11 22:46:30.000000000 -0400
@@ -355,7 +355,7 @@
 ## -Demacs is needed to make some files produce the correct version
 ## for use in Emacs.
 
-cppflags = $(CPPFLAGS) -Demacs -I. -I$(SRC) $(c_switch_all)
+cppflags = -I. -I$(SRC) $(CPPFLAGS) -Demacs $(c_switch_all)
 cflags   = $(CFLAGS) $(cppflags)
 #if defined (WIN32_NATIVE)
 ldflags  = $(LDFLAGS) -mwindows -e _mainCRTStartup $(ld_switch_all) $(ld_dynamic_link_flags)