Disabling TBB check fails cmake
The fact that we are having
add_dune_tbb_flags within the TBB find module breaks the CMake check disabling mechanism:
If you run cmake with
-DCMAKE_DISABLE_FIND_PACKAGE_TBB=1 the find module is never executed and any later uses of
add_dune_tbb_flags result in an
Unknown CMake command error. My proposed solution is to move the add function out of the find module.