docker pull elonh/opde:sdk
docker run -it --rm elonh/opde:sdk zsh # or bash
export http_proxy= # [your proxy], do not use localhost or 127.0.0.1
export https_proxy=$http_proxy
opde feeds && opde config -a
make package/feeds/base/fullconenat/compile -j$(nproc) || make package/feeds/base/fullconenat/compile V=s

Applying ./patches/000-printk.patch using plaintext: 
patching file xt_FULLCONENAT.c
Hunk #1 succeeded at 702 (offset 5 lines).
make[4]: Entering directory '/openwrt/build_dir/target-x86_64_musl/linux-x86_64/linux-5.4.117'
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  HOSTCC  scripts/kconfig/confdata.o
  HOSTCC  scripts/kconfig/expr.o
  HOSTCC  scripts/kconfig/lexer.lex.o
  HOSTCC  scripts/kconfig/parser.tab.o
  HOSTCC  scripts/kconfig/preprocess.o
  HOSTCC  scripts/kconfig/symbol.o
  HOSTLD  scripts/kconfig/conf
scripts/kconfig/conf  --syncconfig Kconfig
can't find file Kconfig
make[6]: *** [scripts/kconfig/Makefile:73: syncconfig] Error 1
make[5]: *** [Makefile:590: syncconfig] Error 2
make[4]: *** [Makefile:696: include/config/auto.conf.cmd] Error 2
make[4]: Leaving directory '/openwrt/build_dir/target-x86_64_musl/linux-x86_64/linux-5.4.117'
make[3]: *** [Makefile:68: /openwrt/build_dir/target-x86_64_musl/linux-x86_64/fullconenat-2019-10-21-0cf3b48f/.built] Error 2