Currently the windows python PRE build is failing on azure pipelines, e.g. see here. The fact that it's failing doesn't inherently seem to be an issue, as it looks like numpy is failing to build against the development version of python.

However, pip seems to be trying to repeatedly install numpy, and failing multiple times before the build times out. It seems that pip tries to install the latest version of pandas, fails (as the numpy build fails), so tries the next oldest version of pandas, fails, etc. etc. until the 1 hr timeout is reached.

It would be good if there was a way to stop this happening so the build wasn't going on for the whole hour. Perhaps installing numpy first is the simplest way to fix this? Or installing matplotlib first, before installing the test dependencies?