This is my defconfig slightly modified from configs/raspberrypi3_64_defconfig:

$ cat defconfig 
BR2_aarch64=y
BR2_cortex_a53=y
BR2_ARM_FPU_VFPV4=y

# patches
BR2_GLOBAL_PATCH_DIR="board/raspberrypi/patches"
BR2_DOWNLOAD_FORCE_CHECK_HASHES=y

BR2_SYSTEM_DHCP="eth0"

# Linux headers same as kernel, a 6.6 series
BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_6_6=y

BR2_TOOLCHAIN_BUILDROOT_CXX=y

BR2_LINUX_KERNEL=y
BR2_LINUX_KERNEL_CUSTOM_TARBALL=y
BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="$(call github,raspberrypi,linux,576cc10e1ed50a9eacffc7a05c796051d7343ea4)/linux-576cc10e1ed50a9eacffc7a05c796051d7343ea4.tar.gz"
BR2_LINUX_KERNEL_DEFCONFIG="bcmrpi3"
BR2_LINUX_KERNEL_DTS_SUPPORT=y
BR2_LINUX_KERNEL_INTREE_DTS_NAME="broadcom/bcm2710-rpi-3-b broadcom/bcm2710-rpi-3-b-plus broadcom/bcm2710-rpi-cm3"

BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y

BR2_PACKAGE_RPI_FIRMWARE=y
BR2_PACKAGE_RPI_FIRMWARE_BOOTCODE_BIN=y
BR2_PACKAGE_RPI_FIRMWARE_VARIANT_PI=y
BR2_PACKAGE_RPI_FIRMWARE_CONFIG_FILE="board/raspberrypi3-64/config_3_64bit.txt"

# Required tools to create the SD image
BR2_PACKAGE_HOST_DOSFSTOOLS=y
BR2_PACKAGE_HOST_GENIMAGE=y
BR2_PACKAGE_HOST_MTOOLS=y

# Filesystem / image
BR2_TARGET_ROOTFS_EXT2=y
BR2_TARGET_ROOTFS_EXT2_4=y
BR2_TARGET_ROOTFS_EXT2_SIZE="120M"
# BR2_TARGET_ROOTFS_TAR is not set
BR2_ROOTFS_POST_BUILD_SCRIPT="board/raspberrypi3-64/post-build.sh"
BR2_ROOTFS_POST_IMAGE_SCRIPT="board/raspberrypi3-64/post-image.sh"

# Enable compressed kernel module support
BR2_PACKAGE_BUSYBOX_SHOW_OTHERS=y
BR2_PACKAGE_KMOD_TOOLS=y
BR2_PACKAGE_XZ=y
BR2_PACKAGE_KMOD=y
BR2_PACKAGE_HOST_KMOD_XZ=y

issuing make, this is the last lines of the output:

checking for library containing yywrap... -ll
checking for gawk... (cached) gawk
checking for ln -s or something else... ln -s
checking for __attribute__... no
checking for ld --version-script... yes
checking whether C compiler accepts -Wno-error=enum-conversion... yes
checking whether C compiler accepts -Wno-unused-but-set-variable... yes
checking for openldap... no
checking pkg-config is at least version 0.9.0... yes
checking for MICROHTTPD... no
checking for CJWT... no
checking for CJSON... no
checking for sqlite3... no
checking for libintl... no
checking for crypto library... included libhcrypto
checking if compiling threadsafe libraries... yes
checking for inline... inline
checking for an ANSI C-conforming const... yes
checking for size_t... no
checking for egrep... (cached) /usr/bin/grep -E
checking for pid_t... no
checking for uid_t... no
checking for gid_t... no
checking return type of signal handlers... void
checking for standards.h... no
checking for netinet/ip.h... no
checking for netinet/tcp.h... no
checking for egrep -e... (cached) /usr/bin/grep -E
checking for /home/mark/dev/buildroot/output/host/bin/ccache /usr/bin/gcc  options needed to detect all undeclared functions... cannot detect
configure: error: in '/home/mark/dev/buildroot/output/build/host-heimdal-f4faaeaba371fff3f8d1bc14389f5e6d70ca8e17':
configure: error: cannot make /home/mark/dev/buildroot/output/host/bin/ccache /usr/bin/gcc  report undeclared builtins
See 'config.log' for more details
make[1]: *** [package/pkg-generic.mk:279: /home/mark/dev/buildroot/output/build/host-heimdal-f4faaeaba371fff3f8d1bc14389f5e6d70ca8e17/.stamp_configured] Errore 1
make: *** [Makefile:83: _all] Errore 2

I searched inside the xconfig tool for host-heimdal but I found nothing.
Why does it fail? I mean, I didn’t change nothing about its configuration.

UPDATE

• Buildroot version:2024.08-rc3
• Download method: git clone
• Host version: Ubuntu 24.04