Unknown CMake command "CHECK_CXX_COMPILER_FLAG"

[August Johansson]

I am unable to compile demos with gcc 5.4.0 due to some error with the CHECK_CXX_COMPILER_FLAG. This is on the master branch (pulled today). If I comment line 32 in CMakeLists.txt, the error goes away.

august@felix build (master)$ cmake .. 
-- The C compiler identification is GNU 5.4.0
-- The CXX compiler identification is GNU 5.4.0
-- Check for working C compiler: /usr/lib/ccache/cc
-- Check for working C compiler: /usr/lib/ccache/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/lib/ccache/c++
-- Check for working CXX compiler: /usr/lib/ccache/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features

-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:32 (CHECK_CXX_COMPILER_FLAG):
  Unknown CMake command "CHECK_CXX_COMPILER_FLAG".


-- Configuring incomplete, errors occurred!
See also "/home/august/dev/fenics-dev/dolfin/demo/undocumented/poisson-disc/cpp/build/CMakeFiles/CMakeOutput.log".

[Prof Garth Wells]

Could you try adding include(CheckCXXCompilerFlag)?

[August Johansson]

Yes, that solves problem!

[Prof Garth Wells]

Ass missing include in demo CMake files. Fixes Issue #703.

→ <<cset 8d644106c063>>