11 ~~~＞ openWRT 编译 CLI 包错误 undefined reference to symbol ‘dlsym@@GLIBC_2.2.5‘

本篇博客记录 编译 OpenWRT x86-64 的sysupgrade 包出错解决方法，备忘记录。
增加 Attended sysUpgrade 包，make menuconfig

  -> Base system 
  --> <*> auc............ Attended sysUpgrade CLI (EXPERIMENTAL)

编译出错信息如下：

.......
[100%] Linking C executable auc
/home/robot/OpenWrt/LS1046A-19.07/staging_dir/toolchain-x86_64_gcc-8.3.0_glibc/lib/gcc/x86_64-openwrt-linux-gnu/8.3.0/../../../../x86_64-openwrt-linux-gnu/bin/ld: CMakeFiles/auc.dir/auc.c.o: undefined reference to symbol 'dlsym@@GLIBC_2.2.5'
/home/robot/OpenWrt/LS1046A-19.07/staging_dir/toolchain-x86_64_gcc-8.3.0_glibc/lib/gcc/x86_64-openwrt-linux-gnu/8.3.0/../../../../x86_64-openwrt-linux-gnu/bin/ld: /home/robot/OpenWrt/LS1046A-19.07/staging_dir/toolchain-x86_64_gcc-8.3.0_glibc/x86_64-openwrt-linux-gnu/bin/../../../toolchain-x86_64_gcc-8.3.0_glibc/lib64/libdl.so.2: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
CMakeFiles/auc.dir/build.make:84: recipe for target 'auc' failed
make[6]: *** [auc] Error 1
........

解决过程：

# (1) 进入auc的编译文件夹中
$ cd build_dir/target-x86_64_glibc/auc-0.1.4/

# (2) 修改CMakeList.txt 文件，增加链接依赖库 dl
$ vim CMakeLists.txt
ADD_EXECUTABLE(auc auc.c)
TARGET_LINK_LIBRARIES(auc uci ubox ubus uclient blobmsg_json ${
    
    json} -ldl #增加内容 -ldl )
INSTALL(TARGETS auc RUNTIME DESTINATION sbin)

原因说明:
调用动态链接库，依赖 glibc 库 dlsym ,查看man dlsym 明确指出需要链接参数-ldl， 如下图：