Install prefix for fftw3

I’m modifying a config file template. I’m trying to build 9.6.2 in ubuntu 18.04. I have fftw3 installed from the ubuntu repositrory. The key with_fftw3 apparently points to where the libraries are installed. Mine are under /usr/lib/x86_64-linux-gnux86_64-linux-gnu. Exactly what does the install prefix point to? does it point to the actual directory, or does it point to the directory under which the lib directory sits?


Art Edwards

the install prefix points to the top level directory i.e. the directory under which the lib directory is located.

See also Building Abinit - abinit

If your installation does not follow the PREFIX/bin, PREFIX/lib, …, structure, you might want to use the FFTW3_FCFLAGS (for the includes) and FFTW3_LIBS environment variables.

In case of doubt, you can always consult the config file template in doc/build/config-template.ac9.