title: Why am I getting Error Cannot find source file in cmake?
body: <p>I am trying to create a shared library using the files present in SOURCE. So I added as suggested by <a href="https://stackoverflow.com/questions/8934295/add-source-in-a-subdirectory-to-a-cmake-project">this post</a>. </p>
  
  <pre><code>cmake_minimum_required(VERSION 3.0.2)
  project(myproj)
  
  set (SOURCE
      ${SOURCE}
      ${CMAKE_CURRENT_SOURCE_DIR}/src/io/IO1.cpp
      ${CMAKE_CURRENT_SOURCE_DIR}/src/io/IO2.cpp
  )
  
  add_library(myprojlib SHARED SOURCE)
  </code></pre>
  
  <p>I get error even though I have set the source :</p>
  
  <blockquote>
    <p>CMake Error at CMakeLists.txt:34 (add_library):   Cannot find source
    file:</p>
  
  <pre><code>SOURCE
  </code></pre>
    
    <p>Tried extensions .c .C .c++ .cc .cpp .cxx .m .M .mm .h .hh .h++ .hm
    .hpp   .hxx .in .txx</p>
  </blockquote>