ld: symbol(s) not found for architecture x86_64

[juev]

Sorry for stupid question.

I trying to use yaml-cpp for parsing simple yaml file.
OS: macOS Siera 10.12.2

$ g++ --version
Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin16.3.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

main.cpp:

#include <iostream>
#include <yaml-cpp/yaml.h>

using namespace std;

int main() {
    YAML::Node config = YAML::LoadFile("config.yaml");

    const std::string username = config["username"].as<std::string>();
    const std::string password = config["password"].as<std::string>();

    cout << "username: " << username << endl
         << "password: " << password << endl;

    return 0;
}

When I trying compile this code:

$ g++ main.cpp -o yaml -v

I get error:

Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin16.3.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
 "/Library/Developer/CommandLineTools/usr/bin/clang" -cc1 -triple x86_64-apple-macosx10.12.0 -Wdeprecated-objc-isa-usage -Werror=deprecated-objc-isa-usage -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name main.cpp -mrelocation-model pic -pic-level 2 -mthread-model posix -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu penryn -target-linker-version 274.2 -v -dwarf-column-info -debugger-tuning=lldb -resource-dir /Library/Developer/CommandLineTools/usr/bin/../lib/clang/8.0.0 -stdlib=libc++ -fdeprecated-macro -fdebug-compilation-dir /Users/juev/Projects/CPP -ferror-limit 19 -fmessage-length 158 -stack-protector 1 -fblocks -fobjc-runtime=macosx-10.12.0 -fencode-extended-block-signature -fcxx-exceptions -fexceptions -fmax-type-align=16 -fdiagnostics-show-option -fcolor-diagnostics -o /var/folders/j_/mn1l90j15f92df2p9j_qdfcr0000gn/T/main-015037.o -x c++ main.cpp
clang -cc1 version 8.0.0 (clang-800.0.42.1) default target x86_64-apple-darwin16.3.0
ignoring nonexistent directory "/usr/include/c++/v1"
#include "..." search starts here:
#include <...> search starts here:
 /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1
 /usr/local/include
 /Library/Developer/CommandLineTools/usr/bin/../lib/clang/8.0.0/include
 /Library/Developer/CommandLineTools/usr/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.
 "/Library/Developer/CommandLineTools/usr/bin/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.12.0 -o yaml /var/folders/j_/mn1l90j15f92df2p9j_qdfcr0000gn/T/main-015037.o -lc++ -lSystem /Library/Developer/CommandLineTools/usr/bin/../lib/clang/8.0.0/lib/darwin/libclang_rt.osx.a
Undefined symbols for architecture x86_64:
  "YAML::detail::memory_holder::merge(YAML::detail::memory_holder&)", referenced from:
      YAML::detail::node& YAML::detail::node_data::convert_to_node<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, boost::shared_ptr<YAML::detail::memory_holder>) in main-015037.o
  "YAML::detail::memory::create_node()", referenced from:
      YAML::detail::memory_holder::create_node() in main-015037.o
  "YAML::detail::node_data::set_scalar(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      YAML::detail::node_ref::set_scalar(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) in main-015037.o
  "YAML::detail::node_data::empty_scalar", referenced from:
      YAML::Node::Scalar() const in main-015037.o
  "YAML::detail::node_data::mark_defined()", referenced from:
      YAML::detail::node_ref::mark_defined() in main-015037.o
  "YAML::detail::node_data::convert_to_map(boost::shared_ptr<YAML::detail::memory_holder>)", referenced from:
      YAML::detail::node& YAML::detail::node_data::get<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, boost::shared_ptr<YAML::detail::memory_holder>) in main-015037.o
  "YAML::detail::node_data::insert_map_pair(YAML::detail::node&, YAML::detail::node&)", referenced from:
      YAML::detail::node& YAML::detail::node_data::get<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, boost::shared_ptr<YAML::detail::memory_holder>) in main-015037.o
  "YAML::detail::node_data::set_null()", referenced from:
      YAML::detail::node_ref::set_null() in main-015037.o
  "YAML::LoadFile(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      _main in main-015037.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Whats wrong and how I can resolve this problem?

[jbeder]

Add -lyaml-cpp to your compile command.

[jdluk87]

I am having the same problem @jbeder when I do cmake ; make. When using cmake where exactly should I add -lyaml-cpp?

[KitsuneRal]

I add yaml-cpp to target_link_libraries in my CMakeLists.txt. Disclaimer: I'm building yaml-cpp as a submodule, so there's add_subdirectory(yaml-cpp) before that. But at the same rate the already built library can be in paths ld searches.

[jdluk87]

@KitsuneRal thanks, same issue. Let me paste here the CMakeLists.txt. To give you some context, this is a C++ project that use GTEST for testing. YAML is only a dependency for my code.

cmake_minimum_required(VERSION 2.8)
project(reranker C CXX)
include(CheckCXXCompilerFlag)
include(ExternalProject)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++ -std=c++14 -Wall -fPIC")

option(USE_GTEST "Use google test for unit test" ON)

if(DEFINED OSX)
    set(CMAKE_MACOSX_RPATH 1)
endif()

#---------------------------------------
# source 
#---------------------------------------

set(MODULES
  base 
  parser
)

foreach(module ${MODULES})
  set(moduleDir ${CMAKE_CURRENT_SOURCE_DIR}/src/${module})

  file(GLOB cppFiles ${moduleDir}/*.cpp)
  set(SRC_FILES ${SRC_FILES} ${cppFiles})
endforeach()

include_directories(${CMAKE_CURRENT_SOURCE_DIR}/src)
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)

#---------------------------------------
# dependencies
#---------------------------------------
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/yaml/include)
add_subdirectory(yaml)

# yaml
ExternalProject_Add(yaml
    GIT_REPOSITORY https://github.com/jbeder/yaml-cpp.git
    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_SOURCE_DIR}/build
    PREFIX "${CMAKE_CURRENT_BINARY_DIR}"
  )

# project setup
add_library (${PROJECT_NAME} SHARED ${SRC_FILES})
target_link_libraries(${PROJECT_NAME} ${EXTRA_LIBS})
target_link_libraries(${PROJECT_NAME} yaml-cpp)
add_dependencies(${PROJECT_NAME} yaml)

message("use_gtest=${USE_GTEST}")
if (USE_GTEST)
  message("gtest is used")
  #---------------------------------------
  # gtest
  #---------------------------------------
  ExternalProject_Add(googletest
    GIT_REPOSITORY https://github.com/google/googletest.git
    CMAKE_ARGS -Dgtest_force_shared_crt=ON
    PREFIX "${CMAKE_CURRENT_BINARY_DIR}"
    INSTALL_COMMAND ""
  )
  
  ExternalProject_Get_Property(googletest source_dir)
  include_directories(${source_dir}/googletest/include)
  include_directories(${source_dir}/googlemock/include)
  
  ExternalProject_Get_Property(googletest binary_dir)
  set(GTEST_LIBS_DIR ${binary_dir}/googlemock/gtest)
  set(GMOCK_LIBS_DIR ${binary_dir}/googlemock)
  
  #---------------------------------------
  # testing
  #---------------------------------------
  enable_testing()

  set(TEST_DIRS
    base 
    parser
  )

  foreach(dirName ${TEST_DIRS})
    set(testName ${PROJECT_NAME}-test-${dirName})
    set(testLabel test-${dirName})
    set(dirPath ${CMAKE_CURRENT_SOURCE_DIR}/test/${dirName})
    file(GLOB testFiles ${dirPath}/*.cpp)
    add_executable(${testName} ${SRC_FILES} ${testFiles})
    add_dependencies(${testName} googletest)

    target_link_libraries(${testName}
      ${GTEST_LIBS_DIR}/libgtest.a
      ${GTEST_LIBS_DIR}/libgtest_main.a
      ${GMOCK_LIBS_DIR}/libgmock.a
      ${GMOCK_LIBS_DIR}/libgmock_main.a
    )

    target_link_libraries(${testName} ${CMAKE_THREAD_LIBS_INIT} ${EXTRA_LIBS})
    add_test(${testLabel} ${testName} WORKING_DIRECTORY ${dirPath})
  endforeach()
endif()

[KitsuneRal]

Can't say anything about this: things look pretty much in place. Maybe check your environment and whether yaml-cpp is compiled with proper flags. I'd also check with ldd that the mentioned symbols are indeed in the library. Also, there might be some rogue installation of yaml-cpp in a path ld uses, and ld stumbles over it. This is just a couple of ideas for troubleshooting.

Maybe one sidenote: I'm not sure if you really need add_dependencies(${PROJECT_NAME} yaml), since target_link_libraries already does the same, if I don't mistake. I'm not sure though.

[seisowl]

This happened multi-times to me (with different machines) when I use apt-get to install the yaml-cpp package from Ubuntu. Clone from the git, build and install works (sometimes need a particular version). Make sure you uninstall the package. One of my friends somehow get it in /opt/... directory and it won't work until I found the files and deleted them manually... Today I installed the next generation version 0.6 and it worked (better experience probably because it no longer requires BOOST)!

[dbl001]

I am getting this error with 'yaml' compiling SuperCollider on my iMac.

Undefined symbols for architecture x86_64:
  "YAML::BadConversion::~BadConversion()", referenced from:
      YAML::TypedBadConversion<bool>::~TypedBadConversion() in libsclang.a(SC_LanguageConfig.o)

supercollider/supercollider#5852

Any ideas?