运行报错

[chenzhu005774]

/usr/bin/ld: /usr/local/lib/libhandy.a(event_base.o): in function std::thread::thread<handy::MultiBase::loop()::{lambda()#1}, , void>(handy::MultiBase::loop()::{lambda()#1}&&)': /usr/include/c++/9/thread:126: undefined reference to pthread_create'
/usr/bin/ld: /usr/local/lib/libhandy.a(logging.o): in function std::thread::thread<handy::Logger::maybeRotate()::{lambda()#1}, , void>(handy::Logger::maybeRotate()::{lambda()#1}&&)': /usr/include/c++/9/thread:126: undefined reference to pthread_create'
/usr/bin/ld: /usr/local/lib/libhandy.a(threads.o): in function std::thread::thread<handy::ThreadPool::start()::{lambda()#1}, , void>(handy::ThreadPool::start()::{lambda()#1}&&)': /usr/include/c++/9/thread:126: undefined reference to pthread_create'
collect2: error: ld returned 1 exit status