>>> uboot-tools 2021.07 Extracting
bzcat /tmp/instance-0/dl/uboot-tools/u-boot-2021.07.tar.bz2 | tar --strip-components=1 -C /tmp/instance-0/output-1/build/uboot-tools-2021.07   -xf -
>>> uboot-tools 2021.07 Patching

Applying 0001-drop-configh-from-tools.patch using patch: 
patching file tools/env/fw_env_private.h

Applying 0002-tools-only-in-no-dot-config-targets.patch using patch: 
patching file Makefile
Hunk #1 succeeded at 511 (offset 25 lines).
>>> uboot-tools 2021.07 Configuring
mkdir -p /tmp/instance-0/output-1/build/uboot-tools-2021.07/include/config
touch /tmp/instance-0/output-1/build/uboot-tools-2021.07/include/config/auto.conf
mkdir -p /tmp/instance-0/output-1/build/uboot-tools-2021.07/include/generated
touch /tmp/instance-0/output-1/build/uboot-tools-2021.07/include/generated/autoconf.h
>>> uboot-tools 2021.07 Building
PATH="/tmp/instance-0/output-1/host/bin:/tmp/instance-0/output-1/host/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin" /usr/bin/make -j1 -C /tmp/instance-0/output-1/build/uboot-tools-2021.07 CROSS_COMPILE="/tmp/instance-0/output-1/host/bin/arm-linux-" CFLAGS="-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os -g0 " LDFLAGS="" HOSTCFLAGS="-O2 -I/tmp/instance-0/output-1/host/include" STRIP=/tmp/instance-0/output-1/host/bin/arm-linux-strip CONFIG_FIT=y CONFIG_MKIMAGE_DTC_PATH=dtc CONFIG_FIT_SIGNATURE=y CONFIG_FIT_SIGNATURE_MAX_SIZE=0x10000000 CROSS_BUILD_TOOLS=y tools-only
make[1]: Entering directory '/tmp/instance-0/output-1/build/uboot-tools-2021.07'
  HOSTCC  scripts/basic/fixdep
  UPD     include/config/uboot.release
  UPD     include/generated/version_autogenerated.h
  UPD     include/generated/timestamp_autogenerated.h
  COPY    tools/version.h
  HOSTCC  tools/mkenvimage.o
  HOSTCC  tools/os_support.o
  WRAP    tools/lib/crc32.c
  HOSTCC  tools/lib/crc32.o
  HOSTLD  tools/mkenvimage
  HOSTCC  tools/aisimage.o
In file included from /tmp/instance-0/output-1/host/include/openssl/bio.h:20,
                 from /tmp/instance-0/output-1/host/include/openssl/evp.h:16,
                 from include/image.h:1230,
                 from tools/aisimage.c:9:
/tmp/instance-0/output-1/host/include/openssl/crypto.h:415:13: fatal error: pthread.h: No such file or directory
  415 | #   include <pthread.h>
      |             ^~~~~~~~~~~
compilation terminated.
make[2]: *** [scripts/Makefile.host:112: tools/aisimage.o] Error 1
make[1]: *** [Makefile:2046: tools-only] Error 2
make[1]: Leaving directory '/tmp/instance-0/output-1/build/uboot-tools-2021.07'
make: *** [package/pkg-generic.mk:270: /tmp/instance-0/output-1/build/uboot-tools-2021.07/.stamp_built] Error 2
make: Leaving directory '/tmp/instance-0/buildroot'