🐞 bug report

Affected Rule

pip.parse / whl_library (Pipstar extras resolution)

Is this a regression?

Yes, this worked in rules_python 1.6.3 (non-Pipstar path). The extras fix in #3468 correctly passes extras down the call stack, but a normalization mismatch prevents them from being matched against Requires-Dist markers.

Description

PR #3468 fixed the issue of extras not being passed down in Pipstar. However, extras containing hyphens in requirements.txt are not normalized to underscores before being matched against the wheel's Requires-Dist metadata, which uses the PEP 685-normalized form (underscores).

For example, with sqlalchemy[asyncio,postgresql-asyncpg,postgresql-psycopg2binary]==2.0.36 in requirements.txt, the generated BUILD.bazel for the sqlalchemy whl_library shows:

extras = [
    "asyncio",
    "postgresql-asyncpg",        # hyphens from requirements.txt
    "postgresql-psycopg2binary",
],
requires_dist = [
    # ...
    "asyncpg ; extra == 'postgresql_asyncpg'",             # underscores in wheel metadata
    "psycopg2-binary ; extra == 'postgresql_psycopg2binary'",  # underscores in wheel metadata
    # ...
],

The extras list uses hyphens (postgresql-asyncpg) while Requires-Dist markers use underscores (postgresql_asyncpg). The comparison fails silently, so psycopg2-binary and asyncpg are never added as transitive dependencies of sqlalchemy.

Note that asyncio (no hyphens) works correctly because it doesn't need normalization.

Workaround: Use underscores instead of hyphens in the extras specifier in requirements.in:

sqlalchemy[asyncio,postgresql_psycopg2binary,postgresql_asyncpg]==2.0.36

🔬 Minimal Reproduction

requirements.in:

sqlalchemy[asyncio,postgresql-psycopg2binary,postgresql-asyncpg]==2.0.36
psycopg2-binary~=2.9.9
asyncpg~=0.30.0

MODULE.bazel:

pip = use_extension("@rules_python//python/extensions:pip.bzl", "pip")
pip.parse(
    hub_name = "pypi",
    python_version = "3.11",
    requirements_lock = "//:requirements.txt",
)
use_repo(pip, "pypi")

Then query:

bazel query 'kind("py_library", deps(@pypi//sqlalchemy))' | grep -E 'psycopg|asyncpg'
# Returns empty — psycopg2_binary and asyncpg are missing

On rules_python 1.6.3 (non-Pipstar), the same query correctly returns:

@pypi//psycopg2_binary:pkg
@pypi//asyncpg:pkg

🔥 Exception or Error

No error at build time. At runtime, tests fail with:
ModuleNotFoundError: No module named 'psycopg2'

🌍 Your Environment

Operating System:

  
macOS 15.3.1 (darwin 25.2.0, arm64)
  

Output of bazel version:

  
bazel 8.1.1
  

Rules_python version:

  
1.8.4
  

Anything else relevant?

The root cause appears to be that extras parsed from the requirement string in whl_library.bzl (via requirement(rctx.attr.requirement).extras) preserves the original hyphenated form from requirements.txt, but the Requires-Dist markers in wheel METADATA use PEP 685-normalized names (hyphens → underscores). The matching logic needs to normalize extras before comparison.

Related: #3352, #3468