Should get_requires_for_build_editable return (at least) ["pip>21.3"]?

[ivirshup]

Editable installs via pip<21.3 require a setuptools based build. Otherwise you'll get errors like:

ERROR: File "setup.py" or "setup.cfg" not found. Directory cannot be installed in editable mode: /Users/isaac/github/anndata
(A "pyproject.toml" file was found, but editable mode currently requires a setuptools-based build.)

Would this be solved by having get_requires_for_build_editable to add "pip>21.3" to requirements?

[takluyver]

I don't think so, because older versions of pip won't look at get_requires_for_build_editable, so it won't help them. 😉 Even if they did, it would only be installed in the temporary build environment.

More philosophically, part of the aim of standardising editable installations is that you don't necessarily have to use pip at all - you could implement another frontend which can use the same mechanisms. (I'm not sure there's really any point for editable installs, but even so...)

[ivirshup]

I don't think so, because older versions of pip won't look at get_requires_for_build_editable

Ah yeah, fair. Is there a way to even specify this? I think older versions of pip may just fail before looking at any requirements.

More philosophically, part of the aim of standardising editable installations is that you don't necessarily have to use pip at all - you could implement another frontend which can use the same mechanisms

I like that we can tell new contributors for a set of packages that you create an dev install with pip install -e, and we don't have to care about standardising on a build backend.

I'm not sure there's really any point for editable installs

Would you consider the symlink install editable?

[takluyver]

Is there a way to even specify this?

The mechanism for editable installs was only standardised recently. Before that it was just a setuptools feature that pip knew about. Creating a setup.py which gives a helpful error message for python setup.py develop might do it - I don't know exactly what pip does if there's both pyproject.toml and setup.py.

Would you consider the symlink install editable?

In case it wasn't clear, I meant there's not much point creating an alternative frontend for editable installs, as I think pip install -e . covers the only thing you'd want it for. I can definitely see the use of editable installs in general.

I do consider the symlink install as a variant of editable installation. Unfortunately, it's one that's not possible with the new standard mechanism.