The mistake made in #30912 broke the direct use of src/setup.py. (Did not affect normal build.)
Depends on #30912
CC:  @jhpalmieri @tobiasdiez @isuruf
Component: build
Author: Matthias Koeppe
Branch/Commit: 043d3ab
Reviewer: John Palmieri
Issue created by migration from https://trac.sagemath.org/ticket/31357