title: Troubles installing Numpy 1.19.5 with Python 3.9.1 on macOS BigSur
body: <p>Like the title says, I'm on macOS Big Sur 11.1 with Apple silicon. I Just installed Python 3.9.1 from the downloadable link on python.org. When I try to install Numpy 1.19.5 as follows:</p>
  <pre><code>python3 -m pip install numpy -U
  </code></pre>
  <p>I get the following (truncated) output:</p>
  <pre><code>Collecting numpy
    Using cached numpy-1.19.5.zip (7.3 MB)
    Installing build dependencies ... done
    Getting requirements to build wheel ... done
      Preparing wheel metadata ... done
  Building wheels for collected packages: numpy
    Building wheel for numpy (PEP 517) ... error
  .
  .
  .
    ----------------------------------------
    ERROR: Failed building wheel for numpy
  Failed to build numpy
  ERROR: Could not build wheels for numpy which use PEP 517 and cannot be installed directly
  </code></pre>
  <p>I've tried downgrading numpy as follows:</p>
  <pre><code>python3 -m pip install numpy==1.15.3
  </code></pre>
  <p>and I get similar errors. Thanks in advance!</p>