From @saraedum on zulip:
I am building SageMath from source following the guide that uses conda packages. I find that pip install --no-build-isolation -v -v --editable src always recompiles all the extension modules.

As a fix for Sage 9.7, we set an upper bound for setuptools that excludes the new editable wheels feature introduced in 64.0.0. See #34344, #34209 for follow-ups

CC: @saraedum @isuruf @tobiasdiez @dimpase

Component: build

Author: Matthias Koeppe

Branch/Commit: 8ff3894

Reviewer: Julian Rüth

Issue created by migration from https://trac.sagemath.org/ticket/34442