Ability to specify universal2 wheel packages in a marker

[danrossi]

I've been trying to get locally merged universal2 wheels working for packages that don't supply them I ran into many bugs getting them installed via pipenv. But have run into another issue where installing httptools installs the arm64 version when the universal2 wheel is required.

A marker to specify that would be nice if not documented.

I have to then download the specific wheel like the others and set it up for installation in Pipenv but found a bug where it won't choose the local wheel and has to be installed manually.

I tried

pipenv run pip install --implementation py httptools 

but failed

It currently looks like this in the Pipfile but should be specific for macos

httptools = "*"

[matteius]

Pipenv already supports platform_machine as a marker — both as a shorthand Pipfile key and inside the markers field. For example:

[packages]
# Shorthand form:
httptools = {version = "*", platform_machine = "== 'arm64'"}

# Full markers form:
httptools = {version = "*", markers = "sys_platform == 'darwin' and platform_machine == 'arm64'"}

However, it's important to note that PEP 508 markers control whether a package is installed (conditional installation), not which wheel variant pip selects. There is no marker value for universal2 — that's a macOS wheel compatibility tag, not a platform_machine value. On an Apple Silicon Mac, platform_machine evaluates to 'arm64'.

For installing a specific universal2 wheel, you have a few options:

1. Local wheel file via file or path:

   [packages]
   httptools = {file = "wheels/httptools-0.6.1-cp313-cp313-macosx_11_0_universal2.whl"}

2. Pass --platform to pip via extra args:

   PIPENV_EXTRA_PIP_ARGS='["--platform", "macosx_11_0_universal2", "--only-binary", ":all:"]' pipenv install httptools

This was a documentation gap — PR #6539 adds documentation for the shorthand marker keys and architecture-specific examples.