building custom version fails with "glibc cannot be compiled without optimization" error

################################################################################
# setup system defaults
################################################################################

  # The TARGET_CPU variable controls which processor should be targeted for
  # generated code.
    case $TARGET_ARCH in
      x86_64)
        # (AMD CPUs)    k8 k8-sse3 opteron opteron-sse3 athlon64 athlon64-sse3
        #               athlon-fx amdfam10 barcelona
        # (Intel CPUs)  atom core2 nocona
        #
        TARGET_CPU="skylake"
        TARGET_FEATURES="64bit aes mmx mmxext pclmul popcnt rdrand sse sse2 sse3 sse4_1 sse4_2 ssse3"
        ;;
    esac

  # Bootloader to use (syslinux / u-boot)
    BOOTLOADER="syslinux"

  # u-boot version to use (default)
    UBOOT_VERSION="default"

  # Kernel target
    KERNEL_TARGET="bzImage"

  # Additional kernel make parameters (for example to specify the u-boot loadaddress)
    KERNEL_MAKE_EXTRACMD=""

  # Additional kernel dependencies
    KERNEL_EXTRA_DEPENDS_TARGET=""

  # Kernel to use. values can be:
  # default:  default mainline kernel
    LINUX="default"


################################################################################
# setup build defaults
################################################################################

  # Project CFLAGS
    PROJECT_CFLAGS="-O2"

  # SquashFS compression method (gzip / lzo / xz / zstd)
    SQUASHFS_COMPRESSION="gzip"


################################################################################
# setup project defaults
################################################################################

  # build and install ALSA Audio support (yes / no)
    ALSA_SUPPORT="yes"

  # OpenGL(X) implementation to use (no / mesa)
    OPENGL="mesa"

  # OpenGL-ES implementation to use (no / bcm2835-driver / gpu-viv-bin-mx6q)
    OPENGLES="no"

  # include uvesafb support (yes / no)
    UVESAFB_SUPPORT="yes"

  # Displayserver to use (x11 / no)
    DISPLAYSERVER="x11"

  # KODI Player implementation to use (default / bcm2835-driver / libfslvpuwrap)
    KODIPLAYER_DRIVER="default"

  # Modules to install in initramfs for early boot
    INITRAMFS_MODULES=""

  # additional Firmware to use (dvb-firmware, misc-firmware, wlan-firmware)
  # Space separated list is supported,
  # e.g. FIRMWARE="dvb-firmware misc-firmware wlan-firmware"
    FIRMWARE="misc-firmware wlan-firmware dvb-firmware iwlwifi-firmware"

  # additional drivers to install:
  # for a list of additional drivers see packages/linux-drivers
  # Space separated list is supported,
  # e.g. ADDITIONAL_DRIVERS="DRIVER1 DRIVER2"
    ADDITIONAL_DRIVERS="$ADDITIONAL_DRIVERS bcm_sta intel_nuc_led"

  # build and install driver addons (yes / no)
    DRIVER_ADDONS_SUPPORT="yes"

  # driver addons to install:
  # for a list of additional drivers see packages/linux-driver-addons
  # Space separated list is supported,
    DRIVER_ADDONS="crazycat digital_devices dvb-latest"

  # Default size of the ova image, in MB, eg. 4096
    OVA_SIZE="4096"