MXnet Conflicts with Numpy on install

Following Installation instructions for Dive into Deep Learning.

  • Install latest Anaconda 3
  • Run pip install -U d2l => everything updates nicely, including numpy to 1.20
  • Run pip install mxnet==1.7.0.post1. Proceeds to look for numpy 1.17, then tries for cached and ultimately fails in building Wheels. So if -D d2l updated to numpy 1.20, why is mxnet install looking for numpy?

Collecting numpy<1.17.0,>=1.8.2
Using cached (5.1 MB)