cross-rs/cross · warning

unable to get metadata for package

Error message

unable to get metadata for package

What it means

`cargo_metadata_with_args` (src/cargo.rs:158) runs `cargo metadata` for the package. When the command exits non-zero, cross logs the warning "unable to get metadata for package", dumps the indented stderr at debug level, and returns `Ok(None)` — the caller (`cargo_metadata`, `run`) must then handle the missing metadata. It is a warning surfaced to the user, not a panic; the actual cargo error text is hidden unless debug logging is on.

Solutions

1. Re-run with `-vv` / `--verbose` (or RUST_LOG=debug) to see the indented stderr from cargo metadata, which names the real cause
2. Fix the underlying Cargo.toml / feature list error reported by running `cargo metadata --format-version 1` manually
3. Check network/proxy settings or vendored/offline configuration if the failure is a registry fetch
4. Ensure the `--features` values passed to cross exist in Cargo.toml

Example fix

// before
cross build --target aarch64-unknown-linux-gnu --features featuures-typo
// after
cross build --target aarch64-unknown-linux-gnu --features features-correct  # run `cargo metadata` first to verify

// verify metadata resolves before invoking cross
cargo metadata --format-version 1 >/dev/null || echo "cargo metadata failed — fix Cargo.toml first"
# check features exist
grep -q "^featu\?res" Cargo.toml && grep -q "$FEATURE" Cargo.toml

// callers of cargo_metadata_with_args must handle Ok(None)
match cargo_metadata_with_args(...)? {
    Some(metadata) => proceed(metadata),
    None => eprintln!("metadata unavailable: re-run with -vv to see cargo stderr"),
}

When it happens

Trigger: `cargo metadata` failing: invalid Cargo.toml, unparsable `--features` list passed via args, a dependency that fails to resolve, an offline/network failure fetching the registry index, or a broken workspace.

Common situations: Typo in a feature name passed to cross, malformed Cargo.toml after an edit, network is down / CARGO_NET_OFFLINE with an uncached index, or a workspace member with invalid manifest.

Related errors

• unable to find dockerfile for target
• unable to find native dockerfile named
• no valid choice to pick for image name

AI-assisted analysis of cross-rs/cross@8c1a8aa4b6 (2026-09-13). Data as JSON: /api/errors/b9a414c1b4e257db. Report an issue: GitHub.

Appendix: source

Thrown at src/cargo.rs:158

    if let Some(cd) = cd {
        command.current_dir(cd);
    }
    if let Some(config) = args {
        if let Some(ref manifest_path) = config.manifest_path {
            command.args(["--manifest-path".as_ref(), manifest_path.as_os_str()]);
        }
    } else {
        command.arg("--no-deps");
    }
    if let Some(target) = args.and_then(|a| a.target.as_ref()) {
        command.args(["--filter-platform", target.triple()]);
    }
    if let Some(features) = args.map(|a| &a.features).filter(|v| !v.is_empty()) {
        command.args([String::from("--features"), features.join(",")]);
    }
    let output = command.run_and_get_output(msg_info)?;
    if !output.status.success() {
        msg_info.warn("unable to get metadata for package")?;
        let indented = shell::indent(&String::from_utf8(output.stderr)?, shell::default_ident());
        msg_info.debug(indented)?;
        return Ok(None);
    }
    let manifest: Option<CargoMetadata> = serde_json::from_slice(&output.stdout)?;
    manifest
        .map(|m| -> Result<_> {
            Ok(CargoMetadata {
                target_directory: args
                    .and_then(|a| a.target_dir.clone())
                    .unwrap_or(m.target_directory),
                ..m
            })
        })
        .transpose()
}

/// Pass-through mode

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