Hi,

I'm aiming to install mpi4py-fft using pip.
However, I ended up with the following error

[...]
 Error compiling Cython file:
 ------------------------------------------------------------
 ...
 cimport fftwf_xfftn
 ^
 ------------------------------------------------------------
 
 mpi4py_fft/fftw/fftwf_xfftn.pyx:1:8: 'fftwf_xfftn.pxd' not found
[...]
 Cython.Compiler.Errors.CompileError: /scratch/pip-build-bwiiwole/mpi4py-fft/mpi4py_fft/fftw/fftwf_xfftn.pyx

The error is reproducible under various conditions

• mpi4py_fft versions (master, 2.0.5 - 2.0.0)
• gnu compiler version (11, 9)
• python version (3.6,3.7,3.9,3.10)
• operating systems (Ubuntu 22.04.3 LTS, Red Hat Enterprise Linux release 8.6 (Ootpa))

I would be grateful for any hint on how to resolve this issue.

Best,
Sebastian