Cmake doesn't find Boost

I'm trying to configure a project using CMake, but it fails to find Boost libraries even though they are in the specified folder. I have specified Boost_INCLUDE_DIR, Boost_LIBRARYDIR and BOOST_ROOT , but I still get an error saying that CMake is not able to find Boost. What could be the reason of such error?

Are you sure you are doing it the correct way? The idea is that CMake sets BOOST_INCLUDE_DIR, BOOST_LIBRARYDIR and BOOST_ROOT automatically. Do something like this in CMakeLists.txt:

FIND_PACKAGE(Boost)
IF (Boost_FOUND)
    INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIR})
    ADD_DEFINITIONS( "-DHAS_BOOST" )
ENDIF()

If boost is not installed in a default location and can, thus, not be found by CMake, you can tell CMake where to look for boost like this:

SET(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} "C:/win32libs/boost")
SET(CMAKE_LIBRARY_PATH ${CMAKE_LIBRARY_PATH} "C:/win32libs/boost/lib")

Of course, those two lines have to be before the FIND_PACKAGE(Boost) in CMakeLists.txt.

There is more help available by reading the FindBoost.cmake file itself. It is located in your 'Modules' directory.

A good start is to set(Boost_DEBUG 1) - this will spit out a good deal of information about where boost is looking, what it's looking for, and may help explain why it can't find it.

It can also help you to figure out if it is picking up on your BOOST_ROOT properly.

FindBoost.cmake also sometimes has problems if the exact version of boost is not listed in the Available Versions variables. You can find more about this by reading FindBoost.cmake.

Lastly, FindBoost.cmake has had some bugs in the past. One thing you might try is to take a newer version of FindBoost.cmake out of the latest version of CMake, and stick it into your project folder alongside CMakeLists.txt - then even if you have an old version of boost, it will use the new version of FindBoost.cmake that is in your project's folder.

Good luck.

For me this error was simply because boost wasn't installed so on ubuntu:

sudo apt install build-essential libboost-system-dev libboost-thread-dev libboost-program-options-dev libboost-test-dev

I struggled with this problem for a while myself. It turned out that cmake was looking for Boost library files using Boost's naming convention, in which the library name is a function of the compiler version used to build it. Our Boost libraries were built using GCC 4.9.1, and that compiler version was in fact present on our system; however, GCC 4.4.7 also happened to be installed. As it happens, cmake's FindBoost.cmake script was auto-detecting the GCC 4.4.7 installation instead of the GCC 4.9.1 one, and thus was looking for Boost library files with "gcc44" in the file names, rather than "gcc49".

The simple fix was to force cmake to assume that GCC 4.9 was present, by setting Boost_COMPILER to "-gcc49" in CMakeLists.txt. With this change, FindBoost.cmake looked for, and found, my Boost library files.

I also had a similar problem and discovered that the BOOST_INCLUDE_DIR, BOOST_LIBRARYDIR and BOOST_ROOT env variables must hold absolute paths. HTH!