cmake, build with /MD and find_package(Boost)

Question

I have a library that is a Python extension (pyd) and to be able to debug it I need to compile with Multi-threaded DLL (/MD) Runtime Libraries. This works great until I injected a Boost dependency. But first time I call a Boost function the code crashes with a read access violation exception .

After some investigation it turns out cmake find_package(Boost) pulls in the boost libraries build with a different run-time library ieboost_filesystem-vc140-mt-gd.lib

I have put this in an easy test case.

Build boost using vcpkg:
git clone https://github.com/Microsoft/vcpkg.git
.\bootstrap-vcpkg.bat
vcpkg install boost

This only generates the -mt and -md-gd boost libraries.

CMakeLists.txt

cmake_minimum_required (VERSION 3.6.3)
project (FindMDBoost CXX)
set (CMAKE_CXX_STANDARD 14)

set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /MD")
file (GLOB_RECURSE SOURCES "source.cpp")

set(Boost_DEBUG ON)
set(Boost_USE_STATIC_LIBS ON)
set(Boost_USE_MULTI_THREADED OFF)
find_package(Boost COMPONENTS filesystem REQUIRED)
include_directories(${Boost_INCLUDE_DIRS})

add_executable(testcode ${SOURCES})
target_link_libraries(testcode ${Boost_LIBRARIES})

source.cpp

#include <boost/filesystem/path.hpp>
int main()
{   
    auto path = boost::filesystem::path("c:\\"); // Call  Boost to see if it crashes
}

Run cmake:

mkdir build; cd build    
cmake .. "-DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake"

As you can see in the output cmake still tried to find the wrong run time and ignores my Boost_USE_STATIC_LIBS and Boost_USE_MULTI_THREADED flags!

-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1078 ] _boost_TEST_VERSIONS = 1.65.1;1.65.0;1.65;1.64.0;1.64;1.63.0;1.63;1.62.0;1.62;1.61.0;1.61;1.60.0;1.60;1.59.0;1.59;1.58.0;1.58;1.57.0;1.57;1.56.0;1.56;1.55.0;1.55;1.54.0;1.54;1.53.0;1.53;1.52.0;1.52;1.51.0;1.51;1.50.0;1.50;1.49.0;1.49;1.48.0;1.48;1.47.0;1.47;1.46.1;1.46.0;1.46;1.45.0;1.45;1.44.0;1.44;1.43.0;1.43;1.42.0;1.42;1.41.0;1.41;1.40.0;1.40;1.39.0;1.39;1.38.0;1.38;1.37.0;1.37;1.36.1;1.36.0;1.36;1.35.1;1.35.0;1.35;1.34.1;1.34.0;1.34;1.33.1;1.33.0;1.33
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1080 ] Boost_USE_MULTITHREADED = TRUE
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1082 ] Boost_USE_STATIC_LIBS = 
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1084 ] Boost_USE_STATIC_RUNTIME = 
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1086 ] Boost_ADDITIONAL_VERSIONS = 
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1088 ] Boost_NO_SYSTEM_PATHS = 
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1156 ] Declared as CMake or Environmental Variables:
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1158 ]   BOOST_ROOT = 
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1160 ]   BOOST_INCLUDEDIR = 
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1162 ]   BOOST_LIBRARYDIR = 
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1164 ] _boost_TEST_VERSIONS = 1.65.1;1.65.0;1.65;1.64.0;1.64;1.63.0;1.63;1.62.0;1.62;1.61.0;1.61;1.60.0;1.60;1.59.0;1.59;1.58.0;1.58;1.57.0;1.57;1.56.0;1.56;1.55.0;1.55;1.54.0;1.54;1.53.0;1.53;1.52.0;1.52;1.51.0;1.51;1.50.0;1.50;1.49.0;1.49;1.48.0;1.48;1.47.0;1.47;1.46.1;1.46.0;1.46;1.45.0;1.45;1.44.0;1.44;1.43.0;1.43;1.42.0;1.42;1.41.0;1.41;1.40.0;1.40;1.39.0;1.39;1.38.0;1.38;1.37.0;1.37;1.36.1;1.36.0;1.36;1.35.1;1.35.0;1.35;1.34.1;1.34.0;1.34;1.33.1;1.33.0;1.33
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1263 ] location of version.hpp: C:/dev/vcpkg/installed/x86-windows/include/boost/version.hpp
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1287 ] version.hpp reveals boost 1.66.0
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1363 ] using user-specified Boost_COMPILER = -vc140
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1383 ] _boost_MULTITHREADED = -mt
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1427 ] _boost_RELEASE_ABI_TAG = -
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1429 ] _boost_DEBUG_ABI_TAG = -gd
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1491 ] _boost_LIBRARY_SEARCH_DIRS_RELEASE = C:/dev/vcpkg/installed/x86-windows/lib;NO_DEFAULT_PATH;NO_CMAKE_FIND_ROOT_PATH_boost_LIBRARY_SEARCH_DIRS_DEBUG   = C:/dev/vcpkg/installed/x86-windows/debug/lib;NO_DEFAULT_PATH;NO_CMAKE_FIND_ROOT_PATH
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1641 ] Searching for FILESYSTEM_LIBRARY_RELEASE: boost_filesystem-vc140-mt-1_66;boost_filesystem-vc140-mt;boost_filesystem-mt-1_66;boost_filesystem-mt;boost_filesystem
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:380 ]  Boost_LIBRARY_DIR_RELEASE = C:/dev/vcpkg/installed/x86-windows/lib _boost_LIBRARY_SEARCH_DIRS_RELEASE = C:/dev/vcpkg/installed/x86-windows/lib;NO_DEFAULT_PATH;NO_CMAKE_FIND_ROOT_PATH
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1692 ] Searching for FILESYSTEM_LIBRARY_DEBUG: boost_filesystem-vc140-mt-gd-1_66;boost_filesystem-vc140-mt-gd;boost_filesystem-mt-gd-1_66;boost_filesystem-mt-gd;boost_filesystem-mt;boost_filesystem
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:380 ]  Boost_LIBRARY_DIR_DEBUG = C:/dev/vcpkg/installed/x86-windows/debug/lib _boost_LIBRARY_SEARCH_DIRS_DEBUG = C:/dev/vcpkg/installed/x86-windows/debug/lib;NO_DEFAULT_PATH;NO_CMAKE_FIND_ROOT_PATH
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1641 ] Searching for SYSTEM_LIBRARY_RELEASE: boost_system-vc140-mt-1_66;boost_system-vc140-mt;boost_system-mt-1_66;boost_system-mt;boost_system
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:380 ]  Boost_LIBRARY_DIR_RELEASE = C:/dev/vcpkg/installed/x86-windows/lib _boost_LIBRARY_SEARCH_DIRS_RELEASE = C:/dev/vcpkg/installed/x86-windows/lib;NO_DEFAULT_PATH;NO_CMAKE_FIND_ROOT_PATH
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1692 ] Searching for SYSTEM_LIBRARY_DEBUG: boost_system-vc140-mt-gd-1_66;boost_system-vc140-mt-gd;boost_system-mt-gd-1_66;boost_system-mt-gd;boost_system-mt;boost_system
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:380 ]  Boost_LIBRARY_DIR_DEBUG = C:/dev/vcpkg/installed/x86-windows/debug/lib _boost_LIBRARY_SEARCH_DIRS_DEBUG = C:/dev/vcpkg/installed/x86-windows/debug/lib;NO_DEFAULT_PATH;NO_CMAKE_FIND_ROOT_PATH
-- [ C:/install/cmake-3.10.2-win64-x64/share/cmake-3.10/Modules/FindBoost.cmake:1767 ] Boost_FOUND = 1
-- Boost version: 1.66.0
-- Found the following Boost libraries:
--   filesystem
--   system
-- Configuring done
-- Generating done
-- Build files have been written to: C:/dev/cpptests/FindMDBoost/build

Here is the output from the linking phase.

Update : I build the boost libraries from scratch and the code stopped crashing. So this seems to be a vcpkg issue that is does not build the version of boost I need.
b2 runtime-link=shared -j16
My new CmakeList.txt file

cmake_minimum_required (VERSION 3.6.3)
project (FindMDBoost CXX)
set (CMAKE_CXX_STANDARD 14)

set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /MD")
file (GLOB_RECURSE SOURCES "source.cpp")

include_directories(C:/dev/boost/boost_1_66_0)

link_directories("C:/dev/boost/boost_1_66_0/stage/lib")
add_executable(testcode ${SOURCES})
target_link_libraries(testcode libboost_filesystem-vc141-mt-x32-1_66.lib)

Answer 1

I believe the issue just has to do with how you tell vcpkg to build boost when installing it. You can specify static or dynamic linking by specifying what they call triplets .

So for you: vcpkg install boost --triplet x64-windows-static

This will build the boost libraries for use with static linking.

Answer 2

The version of the library with an -mt is the correct one for linking to /MD; confusingly the static library would have an s but does not seem what you want from the remarks at the beginning. You were loading the mt-gd versions which are just the debug versions of these libraries; I suppose they expect the calling python to be the debug version as well.