cmake_minimum_required(VERSION 2.8)

set(VARIABLE "value")

add_subdirectory(top_directory/vars)

me@host:/tmp>cmake .
-- The C compiler identification is unknown
-- The CXX compiler identification is GNU 7.3.1
-- Check for working C compiler: /usr/bin/g++
-- Check for working C compiler: /usr/bin/g++ -- broken
CMake Error at /usr/share/cmake/Modules/CMakeTestCCompiler.cmake:52 (message):
  The C compiler

    "/usr/bin/g++"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: /tmp/CMakeFiles/CMakeTmp

    Run Build Command:"/usr/bin/gmake" "cmTC_607e9/fast"
    /usr/bin/gmake -f CMakeFiles/cmTC_607e9.dir/build.make CMakeFiles/cmTC_607e9.dir/build
    gmake[1]: Entering directory '/tmp/CMakeFiles/CMakeTmp'
    Building C object CMakeFiles/cmTC_607e9.dir/testCCompiler.c.o
    /usr/bin/g++    -o CMakeFiles/cmTC_607e9.dir/testCCompiler.c.o   -c /tmp/CMakeFiles/CMakeTmp/testCCompiler.c
    /tmp/CMakeFiles/CMakeTmp/testCCompiler.c:2:3: error: #error "The CMAKE_C_COMPILER is set to a C++ compiler"
     # error "The CMAKE_C_COMPILER is set to a C++ compiler"
       ^~~~~
    gmake[1]: *** [CMakeFiles/cmTC_607e9.dir/build.make:66: CMakeFiles/cmTC_607e9.dir/testCCompiler.c.o] Error 1
    gmake[1]: Leaving directory '/tmp/CMakeFiles/CMakeTmp'
    gmake: *** [Makefile:126: cmTC_607e9/fast] Error 2




  CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
  CMakeLists.txt


-- Configuring incomplete, errors occurred!
See also "/tmp/CMakeFiles/CMakeOutput.log".
See also "/tmp/CMakeFiles/CMakeError.log".

cmake --version
cmake version 3.11.1
CMake suite maintained and supported by Kitware (kitware.com/cmake).

gcc --version
gcc (SUSE Linux) 7.3.1 20180323 [gcc-7-branch revision 258812]
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.