title: CMake doesn't find Boost libraries while using android-cmake toolchain file
body: <p>I am trying to make a CMake project for code that uses Boost libraries. I want to build it for Android, and I am using this project as a reference: <a href="https://code.google.com/p/android-cmake/">https://code.google.com/p/android-cmake/</a>.</p>
  
  <p>I want to use Boost static libraries that I previously built for android and not make them part of the project to compile.</p>
  
  <p>This is my CMakeLists.txt for the project part that uses Boost</p>
  
  <pre><code>#BOOST
  
  set(BOOST_ROOT /home/neb/workspace/SDLActivityCMAKE/jni/boost)
  
  set(Boost_INCLUDE_DIR /home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53)
  set(BOOST_INCLUDEDIR /home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53)
  set(Boost_LIBRARY_DIR /home/neb/workspace/SDLActivityCMAKE/jni/boost/lib)
  set(BOOST_LIBRARYDIR /home/neb/workspace/SDLActivityCMAKE/jni/boost/lib)
  
  set(Boost_USE_STATIC_LIBS ON)
  set(USE_STATIC_BOOST ON)
  set(Boost_USE_STATIC_RUNTIME ON)
  set(BOOST_COMPILER gcc)
  
  find_package(Boost COMPONENTS "thread-gcc-mt-1_53" "date_time-gcc-mt-1_53" REQUIRED)
  
  include_directories(${Boost_INCLUDE_DIR})
  link_directories(${Boost_LIBRARY_DIR})
  #BOOSTEND
  
  add_executable(main main.cpp)
  target_link_libraries( main ${Boost_LIBRARIES} )
  </code></pre>
  
  <p>When I run regular <code>cmake</code> command (<code>cmake ..</code> from subdir of the jni folder in android project) there is no problem, cmake finds libraries. When I am making cmake to use android.toolchain.cmake provided by the project mentioned above I get this (I am using -DBoost_DEBUG option).</p>
  
  <pre><code>-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:566 ] _boost_TEST_VERSIONS = 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
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:568 ] Boost_USE_MULTITHREADED = TRUE
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:570 ] Boost_USE_STATIC_LIBS = ON
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:572 ] Boost_USE_STATIC_RUNTIME = ON
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:574 ] Boost_ADDITIONAL_VERSIONS = 
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:576 ] Boost_NO_SYSTEM_PATHS = 
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:644 ] Declared as CMake or Environmental Variables:
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:646 ]   BOOST_ROOT = /home/neb/workspace/SDLActivityCMAKE/jni/boost
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:648 ]   BOOST_INCLUDEDIR = /home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:650 ]   BOOST_LIBRARYDIR = /home/neb/workspace/SDLActivityCMAKE/jni/boost/lib
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:652 ] _boost_TEST_VERSIONS = 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
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:734 ] location of version.hpp: /home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53/boost/version.hpp
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:754 ] version.hpp reveals boost 1.53.0
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:786 ] guessed _boost_COMPILER = -gcc46
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:796 ] _boost_MULTITHREADED = -mt
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:839 ] _boost_RELEASE_ABI_TAG = -s
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:841 ] _boost_DEBUG_ABI_TAG = -sd
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:884 ] _boost_LIBRARY_SEARCH_DIRS = /home/neb/workspace/SDLActivityCMAKE/jni/boost/lib;/home/neb/workspace/SDLActivityCMAKE/jni/boost/lib;/home/neb/workspace/SDLActivityCMAKE/jni/boost/stage/lib;/home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53/lib;/home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53/../lib;/home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53/stage/lib;C:/boost/lib;C:/boost;/boost/boost_1_53_0/lib;/boost/boost_1_53/lib;/boost/lib;/boost;/sw/local/lib
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:962 ] Searching for THREAD-GCC-MT-1_53_LIBRARY_RELEASE: boost_thread-gcc-mt-1_53-gcc46-mt-s-1_53;boost_thread-gcc-mt-1_53-gcc46-mt-s;boost_thread-gcc-mt-1_53-mt-s-1_53;boost_thread-gcc-mt-1_53-mt-s;boost_thread-gcc-mt-1_53
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:994 ] Searching for THREAD-GCC-MT-1_53_LIBRARY_DEBUG: boost_thread-gcc-mt-1_53-gcc46-mt-sd-1_53;boost_thread-gcc-mt-1_53-gcc46-mt-sd;boost_thread-gcc-mt-1_53-mt-sd-1_53;boost_thread-gcc-mt-1_53-mt-sd;boost_thread-gcc-mt-1_53-mt;boost_thread-gcc-mt-1_53
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:962 ] Searching for DATE_TIME-GCC-MT-1_53_LIBRARY_RELEASE: boost_date_time-gcc-mt-1_53-gcc46-mt-s-1_53;boost_date_time-gcc-mt-1_53-gcc46-mt-s;boost_date_time-gcc-mt-1_53-mt-s-1_53;boost_date_time-gcc-mt-1_53-mt-s;boost_date_time-gcc-mt-1_53
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:994 ] Searching for DATE_TIME-GCC-MT-1_53_LIBRARY_DEBUG: boost_date_time-gcc-mt-1_53-gcc46-mt-sd-1_53;boost_date_time-gcc-mt-1_53-gcc46-mt-sd;boost_date_time-gcc-mt-1_53-mt-sd-1_53;boost_date_time-gcc-mt-1_53-mt-sd;boost_date_time-gcc-mt-1_53-mt;boost_date_time-gcc-mt-1_53
  -- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:1108 ] Boost_FOUND = FALSE
  CMake Error at /usr/share/cmake-2.8/Modules/FindBoost.cmake:1195 (message):
    Unable to find the requested Boost libraries.
  
    Boost version: 1.53.0
  
    Boost include path:
    /home/neb/workspace/SDLActivityCMAKE/jni/boost/include/boost-1_53
  
    The following Boost libraries could not be found:
  
            boost_thread-gcc-mt-1_53
            boost_date_time-gcc-mt-1_53
  
    No Boost libraries were found.  You may need to set BOOST_LIBRARYDIR to the
    directory containing Boost libraries or BOOST_ROOT to the location of
    Boost.
  Call Stack (most recent call first):
    src/CMakeLists.txt:15 (find_package)
  
  
  -- Configuring incomplete, errors occurred!
  </code></pre>
  
  <p>So I see that CMake is searching for libraries in this exact directory:
  <code>/home/neb/workspace/SDLActivityCMAKE/jni/boost/lib</code>
  In which there are compiled static libraries:</p>
  
  <pre><code>neb@neb-VirtualBox:~/workspace/SDLActivityCMAKE/jni/boost/lib$ ls -l
  total 24440
  -rwxrwxrwx 1 neb neb   557190 sie 27 12:36 libboost_date_time-gcc-mt-1_53.a
  -rwxrwxrwx 1 neb neb  1348474 sie 27 12:36 libboost_filesystem-gcc-mt-1_53.a
  -rwxrwxrwx 1 neb neb   827216 sie 27 12:36 libboost_iostreams-gcc-mt-1_53.a
  -rwxrwxrwx 1 neb neb  6813972 sie 27 12:36 libboost_program_options-gcc-mt-1_53.a
  -rwxrwxrwx 1 neb neb 12927086 sie 27 12:37 libboost_regex-gcc-mt-1_53.a
  -rwxrwxrwx 1 neb neb  1197696 sie 27 12:37 libboost_signals-gcc-mt-1_53.a
  -rwxrwxrwx 1 neb neb   159462 sie 27 12:36 libboost_system-gcc-mt-1_53.a
  -rwxrwxrwx 1 neb neb  1177994 sie 27 12:37 libboost_thread-gcc-mt-1_53.a`
  </code></pre>
  
  <p>I set all variables pointing to BOOST directories I could find, I set variables saying that Boost libraries should be static, but it still doesn't find them. What else can I do?</p>