Get rid of CMake warning 'Manually-specified variables were not used by the project' -

what preferred way touch variable, inside cmakelists.txt?

i've got bunch of similar externalprojects called in loop same variables. of projects don't need specific variables.

you disable warning all-together passing --no-warn-unused-cli cmake. see: https://cmake.org/cmake/help/v3.5/manual/cmake.1.html

touching variable explicitly not wanted according 1 of cmake authors: https://cmake.org/pipermail/cmake/2011-february/042908.html

nevertheless, variables passed -dfoo=bar -dbar=3 -dbaz=true can add line

set(ignoreme "${foo}${baz}${bar}") 

to 1 of cmakelists.txt should enough suppress warning.