enumerator value is not an integer constant

got report from fwts github,
https://github.com/fwts/fwts/issues/13

Attempting to build 23.11.00 on Gentoo Linux with GCC 13

libtool: compile: x86_64-pc-linux-gnu-gcc -DHAVE_CONFIG_H -I. -I../../.. -I../../../src/lib/include -I../../../src/libfwtsiasl -I../../../src/acpica/source/include -I../../../src/acpica/source/compiler -DDATAROOTDIR=\"/usr/share\" -Wall -Wextra -Wno-address-of-packed-member -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/lib64/libffi/include -pthread -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -DACPI_DEBUG_OUTPUT -c fwts_firmware.c -fPIC -DPIC -o .libs/libfwts_la-fwts_firmware.o
In file included from ../../../src/lib/include/fwts_binpaths.h:27,
                 from ../../../src/lib/include/fwts.h:163,
                 from fwts_firmware.c:24:
fwts_firmware.c: In function 'fwts_firmware_feature_string':
../../../src/lib/include/fwts_framework.h:264:27: error: enumerator value for 'FWTS_ASSERT_str_too_small_in_line_93' is not an integer constant
  264 | enum { FWTS_CONCAT_EXPAND(FWTS_ASSERT_ ## m ## _in_line_, __LINE__) = 1 / !!(e) }
      | ^~~~~~~~~~~~
../../../src/lib/include/fwts_framework.h:261:27: note: in definition of macro 'FWTS_CONCAT'
  261 | #define FWTS_CONCAT(a, b) a ## b
      | ^
../../../src/lib/include/fwts_framework.h:264:8: note: in expansion of macro 'FWTS_CONCAT_EXPAND'
  264 | enum { FWTS_CONCAT_EXPAND(FWTS_ASSERT_ ## m ## _in_line_, __LINE__) = 1 / !!(e) }
      | ^~~~~~~~~~~~~~~~~~
fwts_firmware.c:93:9: note: in expansion of macro 'FWTS_ASSERT'
   93 | FWTS_ASSERT((n * (sizeof(feature_names[0].name) - 1)) +
      | ^~~~~~~~~~~
../../../src/lib/include/fwts_framework.h:264:27: error: enumerator value for 'FWTS_ASSERT_invalid_feature_names_in_line_98' is not an integer constant
  264 | enum { FWTS_CONCAT_EXPAND(FWTS_ASSERT_ ## m ## _in_line_, __LINE__) = 1 / !!(e) }
      | ^~~~~~~~~~~~
../../../src/lib/include/fwts_framework.h:261:27: note: in definition of macro 'FWTS_CONCAT'
  261 | #define FWTS_CONCAT(a, b) a ## b
      | ^
../../../src/lib/include/fwts_framework.h:264:8: note: in expansion of macro 'FWTS_CONCAT_EXPAND'
  264 | enum { FWTS_CONCAT_EXPAND(FWTS_ASSERT_ ## m ## _in_line_, __LINE__) = 1 / !!(e) }
      | ^~~~~~~~~~~~~~~~~~
fwts_firmware.c:98:9: note: in expansion of macro 'FWTS_ASSERT'
   98 | FWTS_ASSERT(((1UL << n) - 1) == FWTS_FW_FEATURE_ALL,
      | ^~~~~~~~~~~
make[4]: *** [Makefile:928: libfwts_la-fwts_firmware.lo] Error 1
make[4]: Leaving directory '/var/tmp/portage/sys-apps/fwts-23.11.00/work/fwts-23.11.00/src/lib/src'
make[3]: *** [Makefile:380: all-recursive] Error 1
make[3]: Leaving directory '/var/tmp/portage/sys-apps/fwts-23.11.00/work/fwts-23.11.00/src/lib'
make[2]: *** [Makefile:5141: all-recursive] Error 1
make[2]: Leaving directory '/var/tmp/portage/sys-apps/fwts-23.11.00/work/fwts-23.11.00/src'
make[1]: *** [Makefile:830: all-recursive] Error 1
make[1]: Leaving directory '/var/tmp/portage/sys-apps/fwts-23.11.00/work/fwts-23.11.00'
make: *** [Makefile:761: all] Error 2