make error in cmake using a shared/static library tutorial

[opheliagame]

I went through the cmake tutorial and the last example of using the shared or static library is giving me an error in the make step of the process.
$ make
[ 50%] Building CXX object CMakeFiles/libtest.dir/libtest.cpp.o /exploringBB/extras/cmake/usestudentlib/libtest.cpp:1:21: fatal error: Student.h: No such file or directory compilation terminated. CMakeFiles/libtest.dir/build.make:62: recipe for target 'CMakeFiles/libtest.dir/libtest.cpp.o' failed make[2]: *** [CMakeFiles/libtest.dir/libtest.cpp.o] Error 1 CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/libtest.dir/all' failed make[1]: *** [CMakeFiles/libtest.dir/all] Error 2 Makefile:83: recipe for target 'all' failed make: *** [all] Error 2

Can someone explain why this is happening?
This is my CMakeLists.txt

cmake_minimum_required(VERSION 2.8.9)
project (TestLibrary)
#For the shared library:
set ( PROJECT_LINK_LIBS libtestStudent.so )
link_directories( ~/exploringBB/extras/cmake/studentlib_shared/build )
#For the static library:
#set ( PROJECT_LINK_LIBS libtestStudent.a )
#link_directories( ~/exploringBB/extras/cmake/studentlib_static/build )
include_directories("~/exploringBB/extras/cmake/studentlib_shared/include")
add_executable(libtest libtest.cpp)
target_link_libraries(libtest ${PROJECT_LINK_LIBS} )