Analyse following RPM build log snippet. Describe contents accurately, without speculation or suggestions for resolution.            
Your analysis must be as concise as possible, while keeping relevant information intact.
Snippet: 
 CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
  -- Configuring incomplete, errors occurred!
The variable CMAKE_CXX_COMPILER was not set during invocation of the cmake. This caused configuration to be incomplete.