Greetings all, I have a library called test which has a class that uses boost thread and mutex. here is how the includes in my .h file look: #include #include and here are the private vars: boost::mutex connectedPeersMutex_; boost::thread* listenThread_; in the .cpp file i have I use: #include Now here is how I built my library with this Makefile: SRC = test1.cpp test2.cpp OBJ = $(SRC:.cpp=.o) OUT = libtest.a INCLUDES = -I. -I$$BOOST_ROOT CCFLAGS = -g CCC = g++ LDFLAGS = -g .SUFFIXES: .cpp default: $(OUT) .cpp.o: $(CCC) $(INCLUDES) $(CCFLAGS) -c $< -o $@ $(OUT): $(OBJ) ar rcs $(OUT) $(OBJ) clean: rm -f $(OBJ) $(OUT) Makefile.bak now I try to build a second application that simply uses the libtest.a like this: $ g++ -I ~/boost_1_38_0/ -I. main.cpp -omain -L/usr/local/lib/ -L. -ltest -lboost_thread-gcc41-mt-1_38 ./libtest.a(test1.o): In function `test1::StartServer(int, std::basic_string, int)': /home/chris/test1.cpp:337: undefined reference to `boost::thread::thread(boost::function0boost::function_base > const&)' ./libtest.a(test1.o): In function `~ test1': /home/chris/test1.cpp:36: undefined reference to `boost::mutex::~mutex()' /home/chris/test1.cpp:36: undefined reference to `boost::mutex::~mutex()' /home/chris/test1.cpp:36: undefined reference to `boost::mutex::~mutex()' /home/chris/test1.cpp:36: undefined reference to `boost::mutex::~mutex()' /home/chris/test1.cpp:36: undefined reference to `boost::mutex::~mutex()' ./libtest.a(test1.o):/home/chris/test1.cpp:36: more undefined references to `boost::mutex::~mutex()' follow ./libtest.a(test1.o): In function `test1': /home/chris/test1.cpp:8: undefined reference to `boost::mutex::mutex()' /home/chris/test1.cpp:8: undefined reference to `boost::mutex::mutex()' ./libtest.a(test1.o): In function `boost::detail::thread::lock_opsboost::mutex::lock(boost::mutex&)': /usr/include/boost/thread/detail/lock.hpp:33: undefined reference to `boost::mutex::do_lock()' ./libtest.a(test1.o): In function `boost::detail::thread::lock_opsboost::mutex::unlock(boost::mutex&)': /usr/include/boost/thread/detail/lock.hpp:45: undefined reference to `boost::mutex::do_unlock()' collect2: ld returned 1 exit status Any idea why I am getting these undefined references? Thanks! Christina -- View this message in context: http://www.nabble.com/error-while-compiling-application-that-uses-a-static-l... Sent from the Boost - Users mailing list archive at Nabble.com.