>Get petsc to build fftw, then point mpi4py-fft at it:
>export FFTW_INCLUDE_DIR=$PETSC_DIR/$PETSC_ARCH/include
>export FFTW_LIBRARY_DIR=$PETSC_DIR/$PETSC_ARCH/lib
>pip install mpi4py-fft ?

Thanks, that allows pip to install! I'll update the list when I've figured out if this is working.

all the best
--cjc