Don't require setup.py if setup.cfg is present

[bilderbuchi]

First, let me says that this looks like a great tool to bridge the conda and vanilla python packaging worlds, thank you! 👏

Setuptools/pip does not anymore require a setup.py file (if setup.cfg is present). This is reflected in the documentation, e.g. here.

I noticed that, in contrast, setuptools-conda requires a setup.py file. If no setup.py is present, when setuptools-conda.exe build . runs python.exe setup.py dist_conda, it fails with "[Errno 2] No such file or directory".

If run pip install -e . in the same directory, it completes successfully without issue.

pip install -e .
Obtaining file:///blabla/python_template
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
    Preparing wheel metadata ... done
Installing collected packages: demo
  Running setup.py develop for demo
Successfully installed demo-0.1

Do you need a more precise repro procedure, or is this sufficient?

[chrisjbillington]

It would be good to support projects without a setup.py. But setuptools-conda is implemented as a distutils command dist_conda, that is called as python setup.py dist_conda. Do you know if there is a way to call custom distutils commands via e.g. pip for projects that lack a setup.py?

Otherwise I'm thinking one approach could be to temporarily create a stub setup.py

[chrisjbillington]

I think I was reading some code deep in pip or similar that essentially ran a setup.py stub in a little isolated exec() or runpy call without creating a file on disk. I'll check out what they do, seuptools-conda can probably do the same.

[bilderbuchi]

You're probably right -- in the log output above you see that pip says "Running setup.py develop for demo", so it probably creates one itself.

[bilderbuchi]

Indeed, the code in pip to create a shim file can be found here. That file also contains a number of functions make_setuptools_<command>_args, so maybe something along those lines will also be necessary to define for dist_conda?

[bilderbuchi]

Huh, interesting. I just realised that pip install -e . without a setup.py file present only works if a pyproject.toml is present (even if empty), otherwise I get "ERROR: File "setup.py" not found for legacy project". I think this is as it "should" be, see discussion at pypa/pip#9945 (danger: rabbit hole!)

[chrisjbillington]

Thanks for the pointer to pip's shim. I went ahead and did something similar, and I'm pretty happy with it. Let me know if there are any issues.

[bilderbuchi]

Thanks for the quick fix, this works now!