--- gltron-0.70/configure	2003-12-14 09:00:19.000000000 +0000
+++ gltron-0.70-patched/configure	2022-01-10 00:11:14.467260522 +0000
@@ -2805,7 +2805,7 @@
   RANLIB="$ac_cv_prog_RANLIB"
 fi
 
-CFLAGS="-DSEPARATOR=\"'/'\""
+CFLAGS="$CFLAGS -DSEPARATOR=\"'/'\""
 
 # Check whether --enable-warn or --disable-warn was given.
 if test "${enable_warn+set}" = set; then
@@ -3130,7 +3130,7 @@
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   ac_check_lib_save_LIBS=$LIBS
-LIBS="-lGL  $LIBS"
+LIBS="-lgl  $LIBS"
 cat >conftest.$ac_ext <<_ACEOF
 #line 3135 "configure"
 #include "confdefs.h"
@@ -3171,7 +3171,7 @@
 #define HAVE_LIBGL 1
 EOF
 
-  LIBS="-lGL $LIBS"
+  LIBS="-lgl $LIBS"
 
 else
   { { echo "$as_me:3177: error: OpenGL is not installed" >&5