`pip.parse` is installing a Py3.12 version of a (private-index) wheel even though we're using Py3.11

[dougthor42]

🐞 bug report

Affected Rule

• pip.parse

Is this a regression?

I don't think so. Nothing on the Bazel or rules_python side of things have changed when this appeared.

The bug appeared when our internal foobar package was updated from 2.2.10 to 2.2.12.

Description

pip.parse is installing a Py3.12 version of a (private-index) wheel even though we're using Py3.11.

How does rules_python figure out which Python wheel to install if there are multiple wheels for different python versions?

We have an package on our internal private index. It has wheels for two python versions:

foobar-2.2.12-py311-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
foobar-2.2.12-py312-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl

In MODULE.bazel, I set python_version=3.11:

python.toolchain(
    configure_coverage_tool = True,
    python_version = "3.11",
)
...
pip.parse(
    experimental_extra_index_urls = ["https://[redacted]/simple"],
    experimental_index_url = "https://pypi.org/simple",
    hub_name = "pypi",
    python_version = "3.11",
    requirements_lock = "//:requirements.txt",
)

However, the Py3.12 wheel gets installed:

$ cat bazel-bin/.../decoding_test.runfiles/rules_python~~pip~pypi_311_foobar/site-packages/foobar-2.2.12.dist-info/WHEEL 
Wheel-Version: 1.0
Generator: bazel-wheelmaker 1.0
Root-Is-Purelib: true
Tag: py312-none-manylinux_2_17_x86_64
Tag: py312-none-manylinux2014_x86_64
Root-Is-Purelib: False

My requirements.txt has:

foobar==2.2.12 \
    --hash=sha256:b7d2f441650f075a91f80d131673791f2b7face5722105f528916226dbd8e9e4 \
    --hash=sha256:f8eac44fb8f2ca05d2335085651d5471f5f87647fbf1159b566923b7524eff55

• The first hash b7d2...e9e4 is for the 3.11 wheel, as verified by python -m pip hash ./foobar-2.2.12-py311-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
• The 2nd hash f8ea...ff55 is for the 3.12 wheel, as verified by python -m pip hash ./foobar-2.2.12-py312-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl

🔬 Minimal Reproduction

Working on this. Need to find a public pypi package that has separate 3.11 and 3.12 wheels. Know any?

🔥 Exception or Error

bazel build doesn't complain at all. During bazel test, Python throws this:

...
src/.../circuits_for_snake_circuit.py:9: in 
    import foobar
../rules_python~~pip~pypi_311_foobar/site-packages/foobar/__init__.py:4: in 
    from foobar import circuit_generation
E   ImportError: Python version mismatch: module was compiled for Python 3.12, but the interpreter version is incompatible: 3.11.9 (main, Apr 15 2024, 18:24:23) [Clang 17.0.6 ].

🌍 Your Environment

Operating System:

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux rodete
Release:        n/a
Codename:       rodete

Output of bazel version:

$ bazel version
Bazelisk version: v1.19.0
Starting local Bazel server and connecting to it...
Build label: 7.2.0rc1
Build target: @@//src/main/java/com/google/devtools/build/lib/bazel:BazelServer
Build time: Wed May 15 15:57:57 2024 (1715788677)
Build timestamp: 1715788677
Build timestamp as int: 1715788677

Rules_python version:

bazel_dep(name = "bazel_skylib", version = "1.6.1")
bazel_dep(name = "rules_python", version = "0.31.0")

bazel_dep(name = "buildifier_prebuilt", version = "6.4.0", dev_dependency = True)

bazel_dep(name = "rules_python_gazelle_plugin", version = "0.31.0")  # Same vers as rules_python
bazel_dep(name = "gazelle", version = "0.35.0", repo_name = "bazel_gazelle")

git_override(
    module_name = "rules_python",
    commit = "8791cbbaa2336e24555a6b577ed6e19df24d7d88",
    remote = "https://github.com/bazelbuild/rules_python",
)

git_override(
    module_name = "rules_python_gazelle_plugin",
    commit = "8791cbbaa2336e24555a6b577ed6e19df24d7d88",
    remote = "https://github.com/bazelbuild/rules_python",
    strip_prefix = "gazelle",
)

Anything else relevant?

This appeared when we updated foobar from 2.2.10 to 2.2.12.

For 2.2.10, the requirements.txt also had hashes for both Py3.11 and Py3.12.

[aignas]

Yup, this is a know issue that would be fixed by #1917. Could you please try that one?

I would also expect the wheel to be cp312 rather than py312 because the version numbers are specific to an implementation I think. I wonder if our implementation should error out in those cases.

[dougthor42]

Oh sweet! I'll be able to test things tomorrow morning.

I would also expect the wheel to be cp312 rather than py312

(Forgive me if you already know all of this - I'm writing it down mostly for my own sanity.)

TL;DR: I too would expect the wheel to be cp312 rather than py312. However, I don't know the full build stack of our internal foobar package, so it's possible that it wasn't built with cpython. 🤷

The wheel filename is defined by PEP 491 as {distribution}-{version}(-{build tag})?-{python tag}-{abi tag}-{platform tag}.whl and the various tags defined in PEP 425. The tags are implemented in wheel.bdist_wheel.bdist_wheel.get_tag(). Specifically, L343-L352 determine the "language implementation and version tag" {python tag}.

For pure wheels (which foobar is¹, see the cat .../WHEEL results in OP), these lines call python_tag() which simply returns the "py" plus the major version (eg: "py3"). The bdist_wheel class is a subclass of setuptools.Command, which itself is a subclass of the distutils.cmd.Command ABC, both of which state that the values set by initialize_options() may be overwritten during the build (such as by other Commands).

It's possible that whatever build process we're using to make foobar wheels ends up making such modifications to include the minor version "py3" --> "py312".

For non-pure wheels, these lines end up calling functions from a vendored version of the packaging package, specifically packaging.tags.interpreter_name() and packaging.tags.interpreter_version().

interpreter_name() calls sys.implementation.name which typically returns "cpython". This value is then looked up in the tags.INTERPRETER_SHORT_NAMES mapping and converted to the short-form "cp".

...

Whoo, that was fun! I spent way too much time on that though, and while I learned a lot, I didn't find anything to say exactly why we're getting py312 instead of cp312 🤣.

---

I wonder if our implementation should error out in those cases.

Error out in cases where the python tag is py instead of cp? Definitely not - pyXYZ is still technically a valid tag.

Or are you talking about something else?

Footnotes

1. At least I think it is. There are two conflicting Root-Is-Purelib: lines so... 🤷 ↩