package requires consistent Python metadata on published…

Error message

package {} requires consistent Python metadata on published wheels to generate a portable lock

What it means

mise's pipx backend builds a portable lockfile by deriving a single version constraint from the Python package metadata published on wheels. This error is thrown by simple_index_python_requirement when the metadata does not converge to exactly one consistent constraint — the wheel set provides zero or multiple differing constraints — so no deterministic, portable lock can be produced.

Solutions

Pin the package to a version whose published wheels carry one consistent Python requirement constraint
Check the package's PyPI metadata (Requires-Python across its wheels) and pick a release with uniform metadata
Regenerate the lock after upgrading/reinstalling the package so fresh metadata is fetched

Example fix

// before (mise.toml)
[tools]
black = "latest"
// after
[tools]
black = "24.8.0" # pinned to a release with consistent wheel metadata

Defensive patterns

Strategy: validation

Validate before calling

# check wheel metadata consistency before locking
python -c "import json,urllib.request as u;d=json.load(u.urlopen('https://pypi.org/pypi/black/json'));print({v['requires_python'] for v in d['releases'].values() for v in []})"  # or inspect dist metadata: all Requires-Python values must be identical

Prevention

Pin package versions with known-consistent wheel metadata instead of 'latest'
Inspect PyPI Requires-Python fields across the package's releases before locking
Regenerate locks after upstream releases rather than trusting stale metadata

When it happens

Trigger: Locking a pipx-managed Python package whose published wheels expose inconsistent or missing 'Requires-Python'-style constraint metadata, such that the collected constraints list has a length other than 1. Reached via release_python_requirement during lock generation.

Common situations: Locking a package whose maintainers publish wheels with divergent Python requirement strings across versions/platforms; very new or niche packages with sloppy packaging metadata; a package that recently changed its Python version bounds between releases.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of jdx/mise@533346cc37 (2026-09-17). Data as JSON: /api/errors/bef2c79cf1f2d1e4. Report an issue: GitHub.

Appendix: source

Thrown at src/backend/pipx/lock.rs:603

        if PIPXBackend::version_from_distribution_filename(package, &filename).as_deref()
            == Some(version)
            && filename.ends_with(".whl")
        {
            let value = python
                .captures(link.as_str())
                .and_then(|c| c.get(1))
                .map(|v| v.as_str())
                .unwrap_or("");
            constraints.insert(
                value
                    .replace("&gt;", ">")
                    .replace("&lt;", "<")
                    .replace("&amp;", "&"),
            );
        }
    }
    if constraints.len() != 1 {
        bail!(
            "package {} requires consistent Python metadata on published wheels to generate a portable lock",
            package
        );
    }
    Ok(constraints.into_iter().next().unwrap())
}

fn uv_index_url(registry: &str) -> Result<String> {
    let base = registry.split("{}").next().unwrap_or(registry);
    let mut url = url::Url::parse(base)?;
    if url
        .host_str()
        .is_some_and(|host| host == "pypi.org" || host.ends_with(".pypi.org"))
    {
        url.set_path("/simple/");
    } else {
        let path = url.path().trim_end_matches('/').trim_end_matches("/simple");
        url.set_path(&format!("{path}/simple/"));

View on GitHub (pinned to 533346cc37)