Local package when installed with setuptools via 'pip install .' installs the package as 'UNKNOWN'

[solarvenom]

Hi!

Python version: 3.9

Setup Tools version: 58.0.4

I'm using a setup via pyproject.toml

So...my local packages are installed as 'UNKNOWN' when installed via 'pip3 install .'
Apparently you can fix this issue by simply upgrading the setuptools version to a latest, but this is the python and setuptools versions that MacOS 15.3 comes with out of the box and thus I want my packages to be compatible with these versions.

Can anyone help me figure out whats the root of the problem and how can I update my packages to account for those issues?

The RP that produces this error with a CI:
solarvenom/kettled.py#2

Terminal output:

🦇@~/repos/kettled.py$ pip3 install .
Defaulting to user installation because normal site-packages is not writeable
Processing /Users/myuser/repos/kettled.py
  DEPRECATION: A future pip version will change local packages to be built in-place without first copying to a temporary directory. We recommend you use --use-feature=in-tree-build to test your packages with this new behavior before it becomes the default.
   pip 21.3 will remove support for this functionality. You can find discussion regarding this at https://github.com/pypa/pip/issues/7555.
  WARNING: Value for prefixed-purelib does not match. Please report this to <https://github.com/pypa/pip/issues/10151>
  distutils: /private/var/folders/00/5pzdncp521dg0v3yd5kqxcz00000gn/T/pip-build-env-gw0iwwsw/normal/lib/python3.9/site-packages
  sysconfig: /Library/Python/3.9/site-packages
  WARNING: Value for prefixed-platlib does not match. Please report this to <https://github.com/pypa/pip/issues/10151>
  distutils: /private/var/folders/00/5pzdncp521dg0v3yd5kqxcz00000gn/T/pip-build-env-gw0iwwsw/normal/lib/python3.9/site-packages
  sysconfig: /Library/Python/3.9/site-packages
  WARNING: Additional context:
  user = False
  home = None
  root = None
  prefix = '/private/var/folders/00/5pzdncp521dg0v3yd5kqxcz00000gn/T/pip-build-env-gw0iwwsw/normal'
  WARNING: Value for prefixed-purelib does not match. Please report this to <https://github.com/pypa/pip/issues/10151>
  distutils: /private/var/folders/00/5pzdncp521dg0v3yd5kqxcz00000gn/T/pip-build-env-gw0iwwsw/overlay/lib/python3.9/site-packages
  sysconfig: /Library/Python/3.9/site-packages
  WARNING: Value for prefixed-platlib does not match. Please report this to <https://github.com/pypa/pip/issues/10151>
  distutils: /private/var/folders/00/5pzdncp521dg0v3yd5kqxcz00000gn/T/pip-build-env-gw0iwwsw/overlay/lib/python3.9/site-packages
  sysconfig: /Library/Python/3.9/site-packages
  WARNING: Additional context:
  user = False
  home = None
  root = None
  prefix = '/private/var/folders/00/5pzdncp521dg0v3yd5kqxcz00000gn/T/pip-build-env-gw0iwwsw/overlay'
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
  Installing backend dependencies ... done
    Preparing wheel metadata ... done
Building wheels for collected packages: UNKNOWN
  Building wheel for UNKNOWN (PEP 517) ... done
  Created wheel for UNKNOWN: filename=UNKNOWN-0.0.0-py3-none-any.whl size=1791 sha256=764bf81cf0174792814c9a24d6e7bafd51c50633460f89e98e930e0039982aa5
  Stored in directory: /private/var/folders/00/5pzdncp521dg0v3yd5kqxcz00000gn/T/pip-ephem-wheel-cache-k4l2n_ho/wheels/1b/d2/d5/844526918ed3acbfc131a690208d017e90c09ab1592e9d9df8
Successfully built UNKNOWN
Installing collected packages: UNKNOWN
Successfully installed UNKNOWN-0.0.0
WARNING: You are using pip version 21.2.4; however, version 25.0.1 is available.
You should consider upgrading via the '/Library/Developer/CommandLineTools/usr/bin/python3 -m pip install --upgrade pip' command.

[abravalheri]

If you are seeing and UNKOWN the likely root cause of the problem is the wrong version of setuptools being picked up (e.g. a version that doesn't know how to parse pyproject.toml).

This may happen if you have a very very old version of pip that does not handle PEP 517 (or an old version of pip that has a "build enviorment leak" and ends up using the first version of setuptools it finds in the disk instead of using the version specified in pyproject.toml).

The best way to go around of it is to:

1. Make sure your pyproject.toml lists a recent enough version of setuptools in the [build-system] requires field (it seems that you already did that).
2. Make sure you have a recent enough version of pip.

One thing that minimises the chance of this error happening is creating virtual environments for installing your package (python -m venv and virtualenv have options to automatocally install the latest version of pip when creating the virtual environment).

[solarvenom]

Thank you. Updating pip to a latest version did resolve this.
Still it's a pity, because if I'm not mistaken MacOS 15.3 comes with pip v21.2.4, which has this build environment leak bug and is faulty.