Route as '--find-links' replacement

[sinoroc]

I see people are struggling with installing pytorch on Windows, especially with poetry since it does not know how to do something like pip's --find-links option does. Would simpleindex be able to help in such a scenario?

Typically the recommended installation command for Windows looks like:

pip install torch===1.7.0 torchvision===0.8.1 torchaudio===0.7.0 -f https://download.pytorch.org/whl/torch_stable.html

which seems to be impossible to do with poetry.

[uranusjr]

Assuming pytorch’s find-link page is valid HTML5 (I quickly checked and it seems to be the case), you should be able to just route all pytorch-related packages to it:

# Run `simpleindex path/to/this/file.toml` to start the server.
[routes.torch]
source = "http"
to = "https://download.pytorch.org/whl/torch_stable.html"

[routes."torch{suffix}"]
source = "http"
to = "https://download.pytorch.org/whl/torch_stable.html"

[routes."{project}"]
source = "http"
to = "https://pypi.org/simple/{project}/"

[host]
host = "127.0.0.1"
port = 8000

# Add this to `pyproject.toml`
[[tool.poetry.source]]
name = "local"
url = "http://127.0.0.1:8000/"
default = true

This should be able to make Poetry find the packages.

---

I said should be because it does not. Pytorch’s find-links page has links like this

<a href="torch-0.1-cp27-cp27m-macosx_10_6_x86_64.whl">torch-0.1-cp27-cp27m-macosx_10_6_x86_64.whl</a>

Simpleindex uses 302 FOUND to redirect requests to the actual page, and Poetry would resolve href against http://127.0.0.1:8000/pytorch/, i.e. the original URL. pip instead resolves against the redirected URL.

PEP 503 does not really say what should happen when an endpoint returns redirection, but pip’s behaviour is likely more expected by users since that’s what every web browser in the world does, so Poetry should probably match it.

[sinoroc]

Thanks a lot for looking into this.

I think I saw a bug report and PR in poetry's ticket tracker about URL redirections. Maybe it is related:

• Use URL from response to support redirects python-poetry/poetry#3198
• 1.1.4 regression custom repository does not work properly anymore. python-poetry/poetry#3293

[uranusjr]

Yeah, I think those are the exact same issue.

[uranusjr]

I see python-poetry/poetry#3198 has been merged, so should this be closed?

[sinoroc]

@uranusjr Absolutely. Although I lost touch with the topic, I don't see any reason to keep this ticket open. Thanks for answering my initial question.