4d88472 results in run dependencies being required at build time

[sthen]

Describe the bug

Not sure if this was intentional, but it wasn't mentioned in the commit log so I'm assuming not; after 4d88472, sphinx's run dependencies (requests, Pygments docutils, etc) become required at build time and flit-core reports them as missing if not present.

How to Reproduce

Attempt to build sphinx with runtime deps not installed.

Environment Information

Platform:              openbsd7; (OpenBSD-7.6-amd64-64bit-ELF)
Python version:        3.12.9 (main, Feb 28 2025, 13:08:05) [Clang 16.0.6])
Python implementation: CPython
Sphinx version:        8.2.3
Docutils version:      0.21.2
Jinja2 version:        3.1.5
Pygments version:      2.19.1

Sphinx extensions

Additional context

No response

[AA-Turner]

Can you provide logs? There was a bug in Flit (pypa/flit#728; fixed but unreleased), but the fallback to pathlib doesn't require any dependencies.

A

[sthen]

Building with that Flit patch applied avoids the problem. Without, it looked like this:

* Getting build dependencies for wheel...
ERROR Missing dependencies:
        requests>=2.30.0
        Pygments>=2.17
        docutils<0.22,>=0.20
(etc)