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

-- The CXX compiler identification is GNU 8.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /openwrt/staging_dir/toolchain-aarch64_cortex-a53_gcc-8.4.0_musl/bin/aarch64-openwrt-linux-musl-g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Looking for C++ include unistd.h
-- Looking for C++ include unistd.h - found
-- Looking for C++ include stdint.h
-- Looking for C++ include stdint.h - found
-- Looking for C++ include inttypes.h
-- Looking for C++ include inttypes.h - found
-- Looking for C++ include sys/types.h
-- Looking for C++ include sys/types.h - found
-- Looking for C++ include sys/stat.h
-- Looking for C++ include sys/stat.h - found
-- Looking for C++ include fnmatch.h
-- Looking for C++ include fnmatch.h - found
-- Looking for C++ include stddef.h
-- Looking for C++ include stddef.h - found
-- Check size of uint32_t
-- Check size of uint32_t - done
-- Looking for strtoll
-- Looking for strtoll - found
-- Looking for C++ include pthread.h
-- Looking for C++ include pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Check size of pthread_rwlock_t
-- Check size of pthread_rwlock_t - done
-- Configuring done
-- Generating done
CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_ASM_COMPILER
    CMAKE_ASM_COMPILER_LAUNCHER
    CMAKE_C_COMPILER
    CMAKE_C_FLAGS_RELEASE
    CMAKE_EXE_LINKER_FLAGS
    CMAKE_EXPORT_NO_PACKAGE_REGISTRY
    CMAKE_EXPORT_PACKAGE_REGISTRY
    CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY
    CMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY
    CMAKE_FIND_ROOT_PATH_MODE_LIBRARY
    CMAKE_MODULE_LINKER_FLAGS
    DL_LIBRARY


-- Build files have been written to: /openwrt/build_dir/target-aarch64_cortex-a53_musl/gflags-2.2.2
ninja: Entering directory `/openwrt/build_dir/target-aarch64_cortex-a53_musl/gflags-2.2.2'
ninja: error: loading 'build.ninja': No such file or directory
make[3]: *** [Makefile:48: /openwrt/build_dir/target-aarch64_cortex-a53_musl/gflags-2.2.2/.built] Error 1