rhelmot:

gcc -DPROGRAM='"bash"' -DCONF_HOSTTYPE='"x86_64"' -DCONF_OSTYPE='"freebsd"' -DCONF_MACHTYPE='"x86_64-unknown-freebsd"' -DCONF_VENDOR='"unknown"' -DLOCALEDIR='"/nix/store/4y27vmi6wbm6nq0z2sg65ddy9n5h2g8x-bash-interactive-static-x86_64-unknown-freebsd-5.3p3/share/locale"' -DPACKAGE='"bash"' -DSHELL -DHAVE_CONFIG_H -DHEREDOC_PIPESIZE=4096 -I. -I. -I./include -I./lib -I./lib/intl -I/build/bash-5.3/lib/intl -Wno-parentheses -Wno-format-security -g -DCROSS_COMPILING -rdynamic -g -DCROSS_COMPILING -o mksyntax ./mksyntax.c
make[1]: Entering directory '/build/bash-5.3/builtins'
rm -f mksignames.o
making /build/bash-5.3/lib/intl/libintl.h in /build/bash-5.3/lib/intl
gcc -DPROGRAM='"bash"' -DCONF_HOSTTYPE='"x86_64"' -DCONF_OSTYPE='"freebsd"' -DCONF_MACHTYPE='"x86_64-unknown-freebsd"' -DCONF_VENDOR='"unknown"' -DLOCALEDIR='"/nix/store/4y27vmi6wbm6nq0z2sg65ddy9n5h2g8x-bash-interactive-static-x86_64-unknown-freebsd-5.3p3/share/locale"' -DPACKAGE='"bash"' -DSHELL -DHAVE_CONFIG_H -DHEREDOC_PIPESIZE=4096 -I. -I. -I./include -I./lib -I./lib/intl -I/build/bash-5.3/lib/intl -Wno-parentheses -Wno-format-security -g -DCROSS_COMPILING -DBUILDTOOL -c ./support/mksignames.c
make[2]: Entering directory '/build/bash-5.3/lib/intl'
sed -e '/IN_LIBGLOCALE/d'
-e 's,@''HAVE_POSIX_PRINTF''@,1,g'
-e 's,@''HAVE_ASPRINTF''@,1,g'
-e 's,@''HAVE_SNPRINTF''@,1,g'
-e 's,@''HAVE_WPRINTF''@,1,g'
-e 's,@''HAVE_NEWLOCALE''@,1,g'
-e 's,@''ENHANCE_LOCALE_FUNCS''@,0,g'
< ./libgnuintl.in.h > libintl.h
make[2]: Leaving directory '/build/bash-5.3/lib/intl'
rm -f mkbuiltins.o
gcc -c -DHAVE_CONFIG_H -DSHELL -I. -I.. -I.. -I../include -I../lib -I. -I../lib/intl -I/build/bash-5.3/lib/intl -Wno-parentheses -Wno-format-security -DHEREDOC_PIPESIZE=4096 -g -DCROSS_COMPILING mkbuiltins.c
In file included from mkbuiltins.c:46:
../bashansi.h:44:23: error: 'bool' cannot be defined via 'typedef'
44 | typedef unsigned char bool;
| ^~~~
../bashansi.h:44:23: note: 'bool' is a keyword with '-std=c23' onwards
../bashansi.h:44:1: warning: useless type name in empty declaration
44 | typedef unsigned char bool;
| ^~~~~~~
make[1]: *** [Makefile:231: mkbuiltins.o] Error 1
make[1]: Leaving directory '/build/bash-5.3/builtins'
make: *** [Makefile:822: builtins/builtext.h] Error 1
make: *** Waiting for unfinished jobs....
error: Cannot build '/nix/store/1nq20gs1fmvxw3dsknwislrkj33n2ssg-bash-interactive-static-x86_64-unknown-freebsd-5.3p3.drv'.

rhelmot:

gcc -DPROGRAM='"bash"' -DCONF_HOSTTYPE='"x86_64"' -DCONF_OSTYPE='"freebsd"' -DCONF_MACHTYPE='"x86_64-unknown-freebsd"' -DCONF_VENDOR='"unknown"' -DLOCALEDIR='"/nix/store/4y27vmi6wbm6nq0z2sg65ddy9n5h2g8x-bash-interactive-static-x86_64-unknown-freebsd-5.3p3/share/locale"' -DPACKAGE='"bash"' -DSHELL -DHAVE_CONFIG_H -DHEREDOC_PIPESIZE=4096   -I.  -I. -I./include -I./lib -I./lib/intl -I/build/bash-5.3/lib/intl -Wno-parentheses -Wno-format-security  -g -DCROSS_COMPILING -rdynamic -g -DCROSS_COMPILING -o mksyntax ./mksyntax.c
make[1]: Entering directory '/build/bash-5.3/builtins'
rm -f mksignames.o
making /build/bash-5.3/lib/intl/libintl.h in /build/bash-5.3/lib/intl
gcc -DPROGRAM='"bash"' -DCONF_HOSTTYPE='"x86_64"' -DCONF_OSTYPE='"freebsd"' -DCONF_MACHTYPE='"x86_64-unknown-freebsd"' -DCONF_VENDOR='"unknown"' -DLOCALEDIR='"/nix/store/4y27vmi6wbm6nq0z2sg65ddy9n5h2g8x-bash-interactive-static-x86_64-unknown-freebsd-5.3p3/share/locale"' -DPACKAGE='"bash"' -DSHELL -DHAVE_CONFIG_H -DHEREDOC_PIPESIZE=4096   -I.  -I. -I./include -I./lib -I./lib/intl -I/build/bash-5.3/lib/intl -Wno-parentheses -Wno-format-security  -g -DCROSS_COMPILING -DBUILDTOOL -c ./support/mksignames.c
make[2]: Entering directory '/build/bash-5.3/lib/intl'
sed -e '/IN_LIBGLOCALE/d' \
    -e 's,@''HAVE_POSIX_PRINTF''@,1,g' \
    -e 's,@''HAVE_ASPRINTF''@,1,g' \
    -e 's,@''HAVE_SNPRINTF''@,1,g' \
    -e 's,@''HAVE_WPRINTF''@,1,g' \
    -e 's,@''HAVE_NEWLOCALE''@,1,g' \
    -e 's,@''ENHANCE_LOCALE_FUNCS''@,0,g' \
  < ./libgnuintl.in.h > libintl.h
make[2]: Leaving directory '/build/bash-5.3/lib/intl'
rm -f mkbuiltins.o
gcc -c  -DHAVE_CONFIG_H -DSHELL -I. -I..  -I.. -I../include -I../lib -I. -I../lib/intl -I/build/bash-5.3/lib/intl -Wno-parentheses -Wno-format-security -DHEREDOC_PIPESIZE=4096   -g -DCROSS_COMPILING mkbuiltins.c
In file included from mkbuiltins.c:46:
../bashansi.h:44:23: error: 'bool' cannot be defined via 'typedef'
   44 | typedef unsigned char bool;
      |                       ^~~~
../bashansi.h:44:23: note: 'bool' is a keyword with '-std=c23' onwards
../bashansi.h:44:1: warning: useless type name in empty declaration
   44 | typedef unsigned char bool;
      | ^~~~~~~
make[1]: *** [Makefile:231: mkbuiltins.o] Error 1
make[1]: Leaving directory '/build/bash-5.3/builtins'
make: *** [Makefile:822: builtins/builtext.h] Error 1
make: *** Waiting for unfinished jobs....
error: Cannot build '/nix/store/1nq20gs1fmvxw3dsknwislrkj33n2ssg-bash-interactive-static-x86_64-unknown-freebsd-5.3p3.drv'.