title: Import Error with pyFFTW (scipy.fftpack) in Python 3.8
body: <p>I have a numerical simulation program that works fine at the institute I'm in, there I have a Win10 box where I installed Python 3.7.3 64-bit. I am trying to run the same program in my laptop with Manjaro and Python 3.8.1 (It was also 3.7.3 at the time I installed it, but rolling release ¬¬). The problem is that in my laptop I am getting the following error when trying to import pyFFTW</p>
  
  <pre><code>Traceback (most recent call last):
    File "/home/User/Documents/Program.py", line 22, in &lt;module&gt;
      import pyfftw  # Pythonic wrapper for FFTW
    File "/usr/lib/python3.8/site-packages/pyfftw/__init__.py", line 43, in &lt;module&gt;
      from . import interfaces
    File "/usr/lib/python3.8/site-packages/pyfftw/interfaces/__init__.py", line 237, in &lt;module&gt;
      from . import scipy_fftpack
    File "/usr/lib/python3.8/site-packages/pyfftw/interfaces/scipy_fftpack.py", line 65, in &lt;module&gt;
      from scipy.fftpack import (dct, idct, dst, idst, diff, tilbert, itilbert,
  ImportError: cannot import name '_fftpack' from 'scipy.fftpack' (/usr/lib/python3.8/site-packages/scipy/fftpack/__init__.py)
  
  Process finished with exit code 1
  </code></pre>
  
  <p>As far as I can tell the problem is arising from the libraries within the pyFFTW package itself, but I have no idea how to fix it. I tried uninstalling and reinstalling both pyFFTW (1.17.4) and scipy (1.4.1) with little success.</p>
  
  <p>I thought that I could install another version on Python in my Manjaro box and simply "match" all the versions of the packages in the Win box, but I'm looking for a less nuclear solution.</p>
  
  <p>Just for completeness sake, MWE:</p>
  
  <pre><code>$ python
  &gt;&gt;&gt; import pyfftw
  </code></pre>