Boost is using pthread but should use win32 - winapi

Question

I used Cmake gui and the FindBoost module to add Boost as a dependency in my visual studio 2010 c++ project. I set the parameter that tells FindBoost to use the win32 thread library instead of pthread (because I'm running on windows). When i build my code, all the calls to boost libraries compile fine, but boost itself is having a compile error. its failing on
boost\thread\pthread\mutex.hpp line 11
cannot open include file: 'pthread.h': No such file or directory
If I could make it use the win32 library, the mutex.hpp (and all the other files) dont call pthread.h
How do I build so that it uses boost\thread\win32 ?
here is the section of my cmakelists.txt
# include boost
set(BOOST_ROOT "E:/boost_1_58_0/boost_1_58_0")
add_definitions( -DBOOST_ALL_NO_LIB )
find_package(Boost COMPONENTS thread system)
if(Boost_FOUND)
message(STATUS "Boost was found, Success!")
# telling it to use win32 threads not pthreads
set(Boost_THREADAPI "win32")
INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIRS})
LINK_DIRECTORIES(${Boost_LIBRARY_DIRS})
endif()
CMake comes with a module called FindBoost which i used, and it correctly found the boost directory and set the following
Boost_INCLUDE_DIR
E:/boost_1_58_0/boost_1_58_0/
Boost_LIBRARY_DIR
E:/boost_1_58_0/boost_1_58_0/stage/lib
Boost_SYSTEM_LIBRARY_DEBUG
E:/boost_1_58_0/boost_1_58_0/stage/lib/boost_system-vc100-mt-gd-1_58.lib
Boost_SYSTEM_LIBRARY_RELEASE
E:/boost_1_58_0/boost_1_58_0/stage/lib/boost_system-vc100-mt-1_58.lib
Boost_THREAD_LIBRARY_DEBUG
E:/boost_1_58_0/boost_1_58_0/stage/lib/boost_system-vc100-mt-gd-1_58.lib
Boost_THREAD_LIBRARY_RELEASE
E:/boost_1_58_0/boost_1_58_0/stage/lib/boost_thread-vc100-mt-1_58.lib
visual studio project settings
C/C++ -> General -> Additional Include Directories:
...bunch of my other dependencies
E:\boost_1_58_0\boost_1_58_0
Linker -> General -> Additional Library Directories
E:/boost_1_58_0/boost_1_58_0/stage/lib;E:/boost_1_58_0/boost_1_58_0/stage/lib/$(Configuration);%(AdditionalLibraryDirectories)
Linker -> General -> Link Library Dependencies - No
Linker -> General -> Use LIbrary Dependency Inputs - No
Linker -> Input -> Additional Dependencies:
...bunch of my other .libs
boost_thread.lib
boost_system.lib

Answer 1

I fixed the error but I had try what I call the "dumb" way. The "smart" way didnt work. Smart way was reviewing several times the cmakelists code and the visual studio include library settings. i even did a clean and rebuild boost using b2 and manually set threading=multi and link=static because i thought maybe the library just wasnt built correct.
Finally i gave up and tried the dumb way: I cut and pasted the pthread folder and moved it somewhere else, so that it was no longer in the boost/thread folder, only the win32 folder.
I wish i tried it so long ago, because i didnt think that the compilation error would be due to my project's code, but rather an environment setting in the include and linking. But sure enough i got an error showing that in one of my project's files i was directly trying to include that mutex.hpp from the pthread folder. i didnt write this code (its open source) so i couldnt have exactly known, but still i want to slap myself
#include <boost/thread.hpp>
#include <boost/thread/pthread/mutex.hpp>
changing pthread to win32 made the error go away.