Package: fftw3 Version: 3.3.8-2 Besides actual library binaries, building package fftw3 produces some package config files (*.pc) and some cmake files (*.cmake) but only the pkg-config files are installed.
I suggest a minor modification to install the cmake files too: in libfftw3-dev.install, just add the following line: usr/lib/*/cmake/fftw3/*.cmake in libfftw3-dev.dirs, add usr/lib/cmake/fftw3 Best regards.