Difficulties building u-boot for ARM in Nix shell

I’m trying to build u-boot in a Nix shell but I’m getting errors. It looks like the python dev headers are missing. How can I fix this?

nix-shell -p ubootTools gcc-arm-embedded dtc flex bison python swig ncurses

make -j4 ARCH=arm CROSS_COMPILE=arm-none-eabi- Cubietruck_defconfig

make -j4 CROSS_COMPILE=arm-none-eabi-

scripts/kconfig/conf  --syncconfig Kconfig
  UPD     include/config.h
  CFG     u-boot.cfg
  GEN     include/autoconf.mk.dep
  CFG     spl/u-boot.cfg
  GEN     include/autoconf.mk
  GEN     spl/include/autoconf.mk
  UPD     include/generated/dt.h
  UPD     include/generated/timestamp_autogenerated.h
  UPD     include/config/uboot.release
  UPD     include/generated/version_autogenerated.h
  HOSTCC  scripts/dtc/dtc.o
  HOSTCC  scripts/dtc/flattree.o
  SHIPPED scripts/dtc/pylibfdt/libfdt.i
rm -f scripts/dtc/pylibfdt/_libfdt*.so
  PYMOD   scripts/dtc/pylibfdt/_libfdt.so
  HOSTCC  scripts/dtc/fstree.o
  HOSTCC  scripts/dtc/data.o
  HOSTCC  scripts/dtc/livetree.o
===================== WARNING ======================
This board does not use CONFIG_DM_VIDEO Please update
the board to use CONFIG_DM_VIDEO before the v2019.07 release.
Failure to update by the deadline may result in board removal.
See doc/driver-model/migration.rst for more info.
====================================================
  CFGCHK  u-boot.cfg
  HOSTCC  scripts/dtc/treesource.o
  HOSTCC  scripts/dtc/srcpos.o
  CC      lib/asm-offsets.s
  CC      arch/arm/lib/asm-offsets.s
  HOSTCC  scripts/dtc/checks.o
  HOSTCC  scripts/dtc/util.o
  UPD     include/generated/generic-asm-offsets.h
  UPD     include/generated/asm-offsets.h
  LEX     scripts/dtc/dtc-lexer.lex.c
  YACC    scripts/dtc/dtc-parser.tab.h
  YACC    scripts/dtc/dtc-parser.tab.c
  LDS     u-boot.lds
  HOSTCC  scripts/dtc/dtc-lexer.lex.o
  HOSTCC  scripts/dtc/dtc-parser.tab.o
  HOSTLD  scripts/dtc/dtc
In file included from /usr/include/python3.6m/Python.h:8,
                 from scripts/dtc/pylibfdt/libfdt_wrap.c:149:
/usr/include/python3.6m/pyconfig.h:3:12: fatal error: x86_64-linux-gnu/python3.6m/pyconfig.h: No such file or directory
    3 | #  include <x86_64-linux-gnu/python3.6m/pyconfig.h>
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
error: command 'cc' failed with exit status 1
make[3]: *** [scripts/dtc/pylibfdt/Makefile:30: scripts/dtc/pylibfdt/_libfdt.so] Error 1
make[2]: *** [scripts/Makefile.build:419: scripts/dtc/pylibfdt] Error 2
make[1]: *** [scripts/Makefile.build:419: scripts/dtc] Error 2
make: *** [Makefile:577: scripts] Error 2