Undefined Reference to Boost::System::System_Category() When Compiling

undefined reference to boost::system::system_category() when compiling

The boost library you are using depends on the boost_system library. (Not all of them do.)

Assuming you use gcc, try adding -lboost_system to your compiler command line in order to link against that library.

C++ Boost: undefined reference to boost::system::generic_category()

You should link in the libboost_system library. I am not sure about codeblocks, but the g++ command-line option on your platform would be

-lboost_system

undefined reference to 'boost::system::system_category()'

try:

set(BOOST_ROOT <where you built boost>)

find_package(Boost COMPONENTS program_options signals thread system)
find_package(Threads)

...

target_link_libraries(target ${Boost_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
target_include_directories(target PUBLIC SYSTEM ${Boost_INCLUDE_DIRS})

remove these:

boost_signals
boost_thread
boost_program_options
boost_system
pthread

documentation here: https://cmake.org/cmake/help/v3.0/module/FindBoost.html

why undefined reference to `boost::system::generic_category even if I do link against boost_system

The order at which you link your libraries matters, in your case you have library.cpp that apparently uses the boost_system library

library.cpp:(.text+0x25f): undefined reference to `boost::system::generic_category()'
library.cpp:(.text+0x269): undefined reference to `boost::system::generic_category()'
library.cpp:(.text+0x273): undefined reference to `boost::system::system_category()'

To solve this you should move the boost_system library to the end of your link line

g++ -o build/myproject build/main/main.o -L/usr/local/boost/boost_1_52_0/boost/libs -L/usr/lib -Lbuild -L. -lboost_thread -lpthread -lboost_regex -lpq -lmylibrary **-lboost_system** 

Alternatively, build libmylibrary.so as a shared library and link to the boost_system library directly.

undefined reference to `boost::system::generic_category()' when adding boost/asio

The -l option is not a compiler option, it's a linker options, so you're setting it for the wrong variable as CMAKE_CXX_FLAGS are only for the compiler.

Instead use e.g. target_link_libraries to add libraries. Like

target_link_libraries(rcp boost_system)

---

But what you really should do is to find the system-installed Boost libraries and use those. You do that with find_package:

find_package(Boost
    REQUIRED COMPONENTS asio system)

include_directories(${Boost_INCLUDE_DIRS})
target_link_libraries(rcp ${Boost_LIBRARIES})

Undefined reference to boost::system

As you don't have Boost 1.66, you need to link against boost::system:

add_executable(main main.cpp)
target_link_libraries(main ${Boost_SYSTEM_LIBRARY})

---

Related Topics