Ziggo-CaaS-Switch软件配置编译错误：

[ 88%] Built target time_sync_app
  Scanning dependencies of target time_sync
[ 91%] Building C object CMakeFiles/time_sync.dir/time_sync_main_loop.c.o
[ 94%] Linking C executable time_sync
/usr/bin/ld: CMakeFiles/time_sync.dir/time_sync_main_loop.c.o: in function `main':
time_sync_main_loop.c:(.text+0x1be3): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/time_sync.dir/build.make:85: time_sync] Error 1
make[1]: *** [CMakeFiles/Makefile2:80: CMakeFiles/time_sync.dir/all] Error 2
make: *** [Makefile:84: all] Error 2

错误分析：pthread_create 属于线程库，当前链接 time_sync 时没有把线程库真正带进去，所以在最后 ld 阶段失败。其实，undefined reference to pthread_create 是典型的“编译时带了 -lpthread，但链接阶段没有正确链接线程库”的问题。你这个仓库的 CMakeLists.txt 把 -lpthread 塞进了 CMAKE_C_FLAGS，这并不可靠，尤其在可执行文件链接阶段经常失效。

解决步骤：

直接改交换机软件目录下的 CMakeLists.txt：
xx/Ziggo-CaaS-Switch-main/Ziggo-CaaS-Switch-main/Software/Time-Synchronization/CMakeLists.txt

把末尾这两段：

add_executable(time_sync time_sync_main_loop.c)
target_link_libraries(time_sync ${PROJECT_NAME})

add_executable(switch_config switch_config_main.c)
target_link_libraries(switch_config ${PROJECT_NAME})

改成更稳妥的写法： 

find_package(Threads REQUIRED)

add_executable(time_sync time_sync_main_loop.c)
target_link_libraries(time_sync ${PROJECT_NAME} Threads::Threads m)

add_executable(switch_config switch_config_main.c)
target_link_libraries(switch_config ${PROJECT_NAME} Threads::Threads m)

如果你的环境里 Threads::Threads 解析有问题，也可以先用简单版本：

target_link_libraries(time_sync ${PROJECT_NAME} pthread m)
target_link_libraries(switch_config ${PROJECT_NAME} pthread m)

然后重新构建，最好清掉原来的 build 目录重新跑一遍：

cd /path/to/Software/Time-Synchronization
rm -rf build
mkdir build
cd build
cmake ..
make -j