title: Ninja not found by CMake
body: <p>I'm trying to build some code I got from GitHub using CMake, but keep getting the followings errors:</p>
  
  <pre><code>CMake Error: CMake was unable to find a build program corresponding to "Ninja".  CMAKE_MAKE_PROGRAM is not set.  You probably need to select a different build tool.
  CMake Error: Error required internal CMake variable not set, cmake may be not be built correctly.
  Missing variable is:
  CMAKE_C_COMPILER_ENV_VAR
  CMake Error: Error required internal CMake variable not set, cmake may be not be built correctly.
  Missing variable is:
  CMAKE_C_COMPILER
  CMake Error: Could not find cmake module file:/golang/project/src/github.com/devsisters/goquic/libquic/build/debug/CMakeFiles/2.8.11/CMakeCCompiler.cmake
  CMake Error: Error required internal CMake variable not set, cmake may be not be built correctly.
  Missing variable is:
  CMAKE_CXX_COMPILER_ENV_VAR
  CMake Error: Error required internal CMake variable not set, cmake may be not be built correctly.
  Missing variable is:
  CMAKE_CXX_COMPILER
  CMake Error: Could not find cmake module file:/golang/project/src/github.com/devsisters/goquic/libquic/build/debug/CMakeFiles/2.8.11/CMakeCXXCompiler.cmake
  -- Configuring incomplete, errors occurred!
  </code></pre>
  
  <p>How do I set these variables correctly?</p>
  
  <p>I used a <code>./build_libs.sh</code> file that came with the GitHub code to build this.</p>