[PyPI] platform_system parsing problem

[ismail]

Reproducer on linux-aarch64:

pixi.toml

[project]
name = "stats"
channels = ["conda-forge"]
platforms = ["linux-aarch64"]

[dependencies]
python = ">=3.12.*"

[pypi-dependencies]
jupyterlab = '*'

❯ pixi --version
pixi 0.12.0

pixi install results in:

❯ pixi install
ERROR rattler_installs_packages::types::core_metadata: ignoring Requires-Dist: matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin", failed to parse: Version specifier `<0.2.0appnope` doesn't match PEP 440 rules
matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin"
                   ^^^^^^^^^^^^^
ERROR rattler_installs_packages::types::core_metadata: ignoring Requires-Dist: matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin", failed to parse: Version specifier `<0.2.0appnope` doesn't match PEP 440 rules
matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin"
                   ^^^^^^^^^^^^^
ERROR rattler_installs_packages::types::core_metadata: ignoring Requires-Dist: matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin", failed to parse: Version specifier `<0.2.0appnope` doesn't match PEP 440 rules
matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin"
                   ^^^^^^^^^^^^^
✔ Project in /home/ismail/envs/stats is ready to use!

[notatallshaw]

FYI, this does indeed look like an invalid version specification to me. Did the command successfully install?

It would be great if the error message included the parent, i.e. the package which had the requirement with the invalid specifier.

[ismail]

The installation looks good to me:

❯ ls .pixi/env/lib/python3.12/site-packages/matplotlib_inline*
.pixi/env/lib/python3.12/site-packages/matplotlib_inline:
backend_inline.py  config.py  __init__.py

.pixi/env/lib/python3.12/site-packages/matplotlib_inline-0.1.6.dist-info:
HASH  INSTALLER  LICENSE  METADATA  RECORD  WHEEL  top_level.txt

[ismail]

This looks like a parser error to me, the line is

    "matplotlib-inline>=0.1",
    'appnope;platform_system=="Darwin"',

see https://github.com/ipython/ipykernel/blob/main/pyproject.toml#L34C6-L34C13

site-packages/ipykernel-6.0.1.dist-info/METADATA shows that two lines are mangled together:

Requires-Dist: matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin"

Updated the issue title to reflect the real problem.

[ismail]

The issue is not reproducible on macOS, so I'm guessing parsing of platform_system do actually work.

[tdejager]

Sorry, still don't really understand, is this a valid specification?

Requires-Dist: matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin"

specifically the appnope part?

[ismail]

I downloaded https://files.pythonhosted.org/packages/b0/71/348c659f0fbbf526ca77fae9fd31d43a3c90d4d60ae3df6d477055ee90d5/ipykernel-6.28.0-py3-none-any.whl and unpacked it.

ipykernel-6.28.0/ipykernel-6.28.0.dist-info/METADATA shows this

Requires-Dist: appnope; platform_system == 'Darwin'

but if you install with pixi, METADATA shows:

Requires-Dist: matplotlib-inline (<0.2.0appnope,>=0.1.0) ; platform_system == "Darwin"

so there is no appnope version specification. There is a bug in rip/pixi mangling the lines together. Again upstream https://github.com/ipython/ipykernel/blob/main/pyproject.toml#L34C6-L34C13 has

    "matplotlib-inline>=0.1",
    'appnope;platform_system=="Darwin"',

[wolfv]

This error comes from a previous ipykernel version (ipython/ipykernel#709)

I think we could do a better job at reporting the error (add the version it comes from).

I believe pip (and we) just skip over packages with wrong metadata. Not sure if we should show this to the user by default (since they can't change it usually).

[tdejager]

I believe pip (and we) just skip over packages with wrong metadata. Not sure if we should show this to the user by default (since they can't change it usually).

Yeah this is correct, both @baszalmstra and took that behavior from pip.

[ismail]

@wolfv Thank you! I guess we can just do an s/ERROR/Warning/ since it was quite confusing as it did install the package.

[tdejager]

Yeah, that part does seem a bit strange to me, as it explicitly skips the requirement if it can't parse:

https://github.com/prefix-dev/rip/blob/6faf63a6e76b2981335f4cdd14bac2f4f59cc9b6/crates/rattler_installs_packages/src/types/core_metadata.rs#L88C1-L128C1

So I'm guessing the dependency still comes in somewhere down the line?

[tdejager]

Ah, after talking to @wolfv I understand that it is a problem during backtracking, so not really for the package it selected in the end. I think we could make the log a Warning or Debug statement for now. :)