In linuxfromscratch we do a preliminary build of bash in order to
run it later in a chroot environment without any dependencies from the host
system:
./configure --prefix=/usr \
--build=x86_64-pc-linux-gnu \
--host=x86_64-lfs-linux-gnu \
--without-bash-malloc
When we do this, the build runs:
gcc -c -DHAVE_CONFIG_H -DSHELL -I. -I.. -I.. -I../include -I../lib -I. \
-Wno-parentheses -Wno-format-security -DDEBUG -g -DCROSS_COMPILING \
mkbuiltins.c
Looking at ./builtins/mkbuiltins.c we have:
#if !defined (CROSS_COMPILING)
# include <config.h>
...
#include "../bashansi.h"
In bashansi.h there is:
/* If bool is not a compiler builtin, prefer stdbool.h if we have it */
#if !defined (HAVE_C_BOOL)
# if defined (HAVE_STDBOOL_H)
# include <stdbool.h>
# else
# undef bool
typedef unsigned char bool;
# define true 1
# define false 0
# endif
#endif
This fails is using gcc-15 because with cstd-23 'bool' is a keyword and since
config.h is not included, HAVE_C_BOOL is undefined.
This patch fixes the problem:
diff -Naur bash-5.3-rc1.orig/bashansi.h bash-5.3-rc1/bashansi.h
--- bash-5.3-rc1.orig/bashansi.h 2024-03-25 11:17:49.000000000 -0500
+++ bash-5.3-rc1/bashansi.h 2025-05-21 15:15:56.269730519 -0500
@@ -35,17 +35,21 @@
# include "ansi_stdlib.h"
#endif /* !HAVE_STDLIB_H */
-/* If bool is not a compiler builtin, prefer stdbool.h if we have it */
-#if !defined (HAVE_C_BOOL)
-# if defined (HAVE_STDBOOL_H)
-# include <stdbool.h>
-# else
-# undef bool
+/* Explicitly check __STDC_VERSION__ here in addition to HAVE_C_BOOL:
+ in cross-compilation build tools does not include config.h.*/
+#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 202311L
+ /* If bool is not a compiler builtin, prefer stdbool.h if we have it */
+# if !defined (HAVE_C_BOOL)
+# if defined (HAVE_STDBOOL_H)
+# include <stdbool.h>
+# else
+# undef bool
typedef unsigned char bool;
-# define true 1
-# define false 0
+# define true 1
+# define false 0
+# endif
# endif
-#endif
+#endif /* __STDC_VERSION__ < 202311L */
/* Include <stddef.h>, or define substitutes (config.h handles ptrdiff_t). */
#ifdef HAVE_STDDEF_H
