title: CMake not wanting to link with libGL.so
body: <p>I was coding in KDevelop, ant I set up my CMakeLists.txt to include and link against libGL and freeglut.</p>
  
  <p>However, it gave me the following error:
  <code>make[2]: *** No rule to make target '/usr/lib/libGL.so', needed by 'opengl'.  Stop.</code></p>
  
  <p>Here is my CMakeLists.txt: </p>
  
  <pre><code>cmake_minimum_required(VERSION 2.8)
  
  project(opengl)
  add_executable(opengl main.cpp)
  find_package(OpenGL REQUIRED)
  find_package(GLUT REQUIRED)
  include_directories( ${OPENGL_INCLUDE_DIRS}  ${GLUT_INCLUDE_DIRS} )
  
  target_link_libraries(opengl ${OPENGL_LIBRARIES} ${GLUT_LIBRARY} )
  </code></pre>