setuptools: [BUG] recent versions of setuptools broke editable mode

@abravalheri I have reported a regression. Things were working previously and now they don’t. I appreciate the hard work behind the hard problem of packaging, don’t get me wrong. Regressions happen.

It is not true that a local directory used to have, or even has, precedence over installed packages:

• this wasn’t the case in the past
• this is not the case with packages installed without -e.

Since a certain version, the default behaviour of editable packages changed and now presents a noticeable difference w.r.t. normally-installed packages, and present difficulties developing certain repositories layout (a monorepo where the directory name matches the package name, for instance - like psycopg 3 repository).

So, this is a regression. My questions are:

• is this regression wanted? As in, is the current behaviour the wanted behaviour? If so please document it (but with a WARNING, not with obscure options which need a pass-through pip command to activate, hence don’t even appear in pip --help) It would seem exceedingly bizarre to me. I invite you to look at the psycopg readme: we used to suggest to hack on the project using -e, whereas now we should explain setuptools internals.

• is this regression unexpected? It sounds so to me, because other modes work differently (non-editable install, strict-editable, compat-editable). If so, is it expected to be fixed and can it become part of the spec/tests?

Thank you

Sorry for that. I never remember it by heart 😕

These are the options, copied straight from the docs:

pip install -e . --config-settings editable_mode=strict

pip install -e . --config-settings editable_mode=compat

Hi @qci-amos, please note the following caveat for SETUPTOOLS_ENABLE_FEATURES:

Finally, as long as pip allows it, you can use the environment variable SETUPTOOLS_ENABLE_FEATURES=“legacy-editable” to fallback to access the previous implementation and be bug-by-bug compatible.

Pip no longer allows backends to not implement PEP 660. So that is no longer an option.

What’s at stake for me is the ability to use vscode/pylance with my editable repos

I think the right question here is to ask how vscode and pylance allow you to pass customised --config-settings to pip.