Trying out 2024.05-rc1 ran into this issue when using gcc-14. Minimum defconfig below. I saw a patch in patchwork, but it wasn't gcc-14 related and didn't work here when applying it.

libkmod/libkmod-config.c: In function 'conf_files_insert_sorted':
libkmod/libkmod-config.c:797:24: error: implicit declaration of function 'basename' [-Wimplicit-function-declaration]
  797 |                 name = basename(path);
      |                        ^~~~~~~~
libkmod/libkmod-config.c:797:24: warning: nested extern declaration of 'basename' [-Wnested-externs]
libkmod/libkmod-config.c:797:22: error: assignment to 'const char *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
  797 |                 name = basename(path);
      |                      ^
make[3]: *** [Makefile:1771: libkmod/libkmod-config.lo] Error 1
make[3]: *** Waiting for unfinished jobs....
shared/util.c: In function 'path_to_modname':
shared/util.c:177:19: error: implicit declaration of function 'basename' [-Wimplicit-function-declaration]
  177 |         modname = basename(path);
      |                   ^~~~~~~~
shared/util.c:177:19: warning: nested extern declaration of 'basename' [-Wnested-externs]
shared/util.c:177:17: error: assignment to 'char *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
  177 |         modname = basename(path);


BR2_x86_64=y
BR2_TOOLCHAIN_BUILDROOT_MUSL=y
BR2_KERNEL_HEADERS_6_6=y
BR2_BINUTILS_VERSION_2_42_X=y
BR2_GCC_VERSION_14_X=y
BR2_PACKAGE_KMOD=y