https://bugs.gentoo.org/946332
https://build.opensuse.org/projects/openSUSE:Factory/packages/plotutils/files/plotutils-gcc15.patch?expand=1
--- a/include/sys-defines.h
+++ b/include/sys-defines.h
@@ -255,7 +255,7 @@ extern __C_LINKAGE void free (void * ptr
 
 #ifndef __cplusplus
 #ifdef __STDC__
-typedef enum { false = 0, true = 1 } bool;
+# include <stdbool.h>
 #else  /* not __STDC__, do things the old-fashioned way */
 typedef int bool;
 #define false 0
--- a/libxmi/sys-defines.h
+++ b/libxmi/sys-defines.h
@@ -169,7 +169,7 @@ extern __C_LINKAGE void free (void * ptr
 #ifndef __cplusplus
 #ifndef HAVE_BOOL_IN_CC
 #ifdef __STDC__
-typedef enum { false = 0, true = 1 } bool;
+# include <stdbool.h>
 #else  /* not __STDC__, do things the old-fashioned way */
 typedef int bool;
 #define false 0