allow manylinux compatibility override via _manylinux module.

[ChannyClaus]

Summary

resolves #5915, not entirely sure if manylinux_compatible should be a separate field in the JSON returned by the interpreter or there's some way to use the existing platform for it.

Test Plan

ran the below

rm -rf .venv
target/debug/uv venv
# commenting out the line below triggers the change..
# target/debug/uv pip install no-manylinux
target/debug/uv pip install cryptography --no-cache

is there an easy way to add this into the existing snapshot-based test suite? looking around to see if there's a way that doesn't involve something implementation-dependent like mocks.

update: i think the output does differ between these two, so probably we can use that. i lied - that "building..." output seems to be discarded.

[charliermarsh]

Thanks! I can own reviewing this.

[charliermarsh]

Hmm, looking at the source... I think this might be slightly more complicated. We don't just need to check what manylinux compatibility for the current glibc version. We also need to check compatibility for every prior manylinux version... Notice that in pip, they do:

def platform_tags(archs: Sequence[str]) -> Iterator[str]:
    """Generate manylinux tags compatible to the current platform.

    :param archs: Sequence of compatible architectures.
        The first one shall be the closest to the actual architecture and be the part of
        platform tag after the ``linux_`` prefix, e.g. ``x86_64``.
        The ``linux_`` prefix is assumed as a prerequisite for the current platform to
        be manylinux-compatible.

    :returns: An iterator of compatible manylinux tags.
    """
    if not _have_compatible_abi(sys.executable, archs):
        return
    # Oldest glibc to be supported regardless of architecture is (2, 17).
    too_old_glibc2 = _GLibCVersion(2, 16)
    if set(archs) & {"x86_64", "i686"}:
        # On x86/i686 also oldest glibc to be supported is (2, 5).
        too_old_glibc2 = _GLibCVersion(2, 4)
    current_glibc = _GLibCVersion(*_get_glibc_version())
    glibc_max_list = [current_glibc]
    # We can assume compatibility across glibc major versions.
    # https://sourceware.org/bugzilla/show_bug.cgi?id=24636
    #
    # Build a list of maximum glibc versions so that we can
    # output the canonical list of all glibc from current_glibc
    # down to too_old_glibc2, including all intermediary versions.
    for glibc_major in range(current_glibc.major - 1, 1, -1):
        glibc_minor = _LAST_GLIBC_MINOR[glibc_major]
        glibc_max_list.append(_GLibCVersion(glibc_major, glibc_minor))
    for arch in archs:
        for glibc_max in glibc_max_list:
            if glibc_max.major == too_old_glibc2.major:
                min_minor = too_old_glibc2.minor
            else:
                # For other glibc major versions oldest supported is (x, 0).
                min_minor = -1
            for glibc_minor in range(glibc_max.minor, min_minor, -1):
                glibc_version = _GLibCVersion(glibc_max.major, glibc_minor)
                tag = "manylinux_{}_{}".format(*glibc_version)
                if _is_compatible(arch, glibc_version):
                    yield f"{tag}_{arch}"
                # Handle the legacy manylinux1, manylinux2010, manylinux2014 tags.
                if glibc_version in _LEGACY_MANYLINUX_MAP:
                    legacy_tag = _LEGACY_MANYLINUX_MAP[glibc_version]
                    if _is_compatible(arch, glibc_version):
                        yield f"{legacy_tag}_{arch}"

So they're testing _is_compatible against all versions.

[charliermarsh]

Maybe we should just settle for testing the current manylinux version though. Otherwise we'll have to test a bunch of versions and pass that around.

[charliermarsh]

It seems more common that people use blanket implementations anyway:

def manylinux_compatible(*_, **__):  # PEP 600
    return False

[charliermarsh]

The alternative is that we iterate over all glibc versions up to and including the current, call _is_compatible, and then pass back a dictionary.

[charliermarsh]

What do you think @konstin?

[ChannyClaus]

Hmm, looking at the source... I think this might be slightly more complicated. We don't just need to check what manylinux compatibility for the current glibc version. We also need to check compatibility for every prior manylinux version... Notice that in pip, they do:

def platform_tags(archs: Sequence[str]) -> Iterator[str]:
    """Generate manylinux tags compatible to the current platform.

    :param archs: Sequence of compatible architectures.
        The first one shall be the closest to the actual architecture and be the part of
        platform tag after the ``linux_`` prefix, e.g. ``x86_64``.
        The ``linux_`` prefix is assumed as a prerequisite for the current platform to
        be manylinux-compatible.

    :returns: An iterator of compatible manylinux tags.
    """
    if not _have_compatible_abi(sys.executable, archs):
        return
    # Oldest glibc to be supported regardless of architecture is (2, 17).
    too_old_glibc2 = _GLibCVersion(2, 16)
    if set(archs) & {"x86_64", "i686"}:
        # On x86/i686 also oldest glibc to be supported is (2, 5).
        too_old_glibc2 = _GLibCVersion(2, 4)
    current_glibc = _GLibCVersion(*_get_glibc_version())
    glibc_max_list = [current_glibc]
    # We can assume compatibility across glibc major versions.
    # https://sourceware.org/bugzilla/show_bug.cgi?id=24636
    #
    # Build a list of maximum glibc versions so that we can
    # output the canonical list of all glibc from current_glibc
    # down to too_old_glibc2, including all intermediary versions.
    for glibc_major in range(current_glibc.major - 1, 1, -1):
        glibc_minor = _LAST_GLIBC_MINOR[glibc_major]
        glibc_max_list.append(_GLibCVersion(glibc_major, glibc_minor))
    for arch in archs:
        for glibc_max in glibc_max_list:
            if glibc_max.major == too_old_glibc2.major:
                min_minor = too_old_glibc2.minor
            else:
                # For other glibc major versions oldest supported is (x, 0).
                min_minor = -1
            for glibc_minor in range(glibc_max.minor, min_minor, -1):
                glibc_version = _GLibCVersion(glibc_max.major, glibc_minor)
                tag = "manylinux_{}_{}".format(*glibc_version)
                if _is_compatible(arch, glibc_version):
                    yield f"{tag}_{arch}"
                # Handle the legacy manylinux1, manylinux2010, manylinux2014 tags.
                if glibc_version in _LEGACY_MANYLINUX_MAP:
                    legacy_tag = _LEGACY_MANYLINUX_MAP[glibc_version]
                    if _is_compatible(arch, glibc_version):
                        yield f"{legacy_tag}_{arch}"

So they're testing _is_compatible against all versions.

ah, probably should've looked there as well - i can implement the equivalent logic if y'all decide that to be the way to go 🌵

for what it's worth i do think what you point out in #6039 (comment) is probably true 😅

[charliermarsh]

I think we should just document it and move forward as-is.