[BUG] `build --wheel` leaves unnecessary files

[abitrolly]

setuptools version

setuptools==80.9.0

Python version

Python 3.13

OS

Linux

Additional environment information

No response

Description

(originally reported in pypa/build#958)

setuptools creates unnecessary files when building wheels.

Consider this build session with default setuptools backend.

➜  cd /tmp
➜  /tmp mkdir xxx
➜  /tmp cd xxx
➜  xxx tree
.

0 directories, 0 files
➜  xxx touch pyproject.toml
➜  xxx python -m build --wheel
...
Successfully built unknown-0.0.0-py3-none-any.whl
➜  xxx tree
.
├── build
│   └── bdist.linux-x86_64
├── dist
│   └── unknown-0.0.0-py3-none-any.whl
├── pyproject.toml
└── UNKNOWN.egg-info
    ├── dependency_links.txt
    ├── PKG-INFO
    ├── SOURCES.txt
    └── top_level.txt

5 directories, 6 files

Expected behavior

The only relevant files here are:

├── dist
│   └── unknown-0.0.0-py3-none-any.whl
├── pyproject.toml

How to Reproduce

touch pyproject.toml
python -m build --wheel

Output

[AnkitAhlawat7742]

Hi @abitrolly ,

I would like to better understand this behavior, so I have one question. Are you encountering this issue only when the pyproject.toml file is empty, or does it also occur when the file contains the required package definitions and configuration?