I was trying to do a pip install quisk and this then needed a compile linking to FFTW3
Error message was a typical "file not found" for a system header file .... fftw3.h
Brew Package is there
The package was there - but just in case
brew install fftw
Still the same error.
Alter Search path
As the System compile/look search path does not inlude local/ libraries
I then DID
export DYLD_LIBRARY_PATH=/usr/local/lib export LDFLAGS="-L/usr/local/include" export CFLAGS="-I/usr/local/include
To Disable C-Compiler warnings use
export CFLAGS="-I/usr/local/include -w"
All Warnings !!
Just Return-Type Warning