astral-sh/uv · error

Expected the output filename to be `pylock.toml` or `pylock.

Error message

Expected the output filename to be `pylock.toml` or `pylock.<name>.toml`, where `<name>` is non-empty and contains no dots; found `{file_name}`

What it means

Error "Expected the output filename to be `pylock.toml` or `pylock.<name>.toml`, where `<name>` is non-empty and contains no dots; found `{file_name}`" thrown in astral-sh/uv.

Source

Thrown at crates/uv/src/commands/pip/compile.rs:161

    let format = format.unwrap_or_else(|| {
        let extension = output_file.and_then(Path::extension);
        if extension.is_some_and(|ext| ext.eq_ignore_ascii_case("txt")) {
            PipCompileFormat::RequirementsTxt
        } else if extension.is_some_and(|ext| ext.eq_ignore_ascii_case("toml")) {
            PipCompileFormat::PylockToml
        } else {
            PipCompileFormat::RequirementsTxt
        }
    });

    // If the user is exporting to PEP 751, ensure the filename matches the specification.
    if matches!(format, PipCompileFormat::PylockToml) {
        if let Some(file_name) = output_file
            .and_then(Path::file_name)
            .and_then(OsStr::to_str)
        {
            if !is_pylock_toml(file_name) {
                return Err(anyhow!(
                    "Expected the output filename to be `pylock.toml` or `pylock.<name>.toml`, where `<name>` is non-empty and contains no dots; found `{file_name}`",
                ));
            }
        }
    }

    // Respect `UV_PYTHON`
    if python.is_none() && python_version.is_none() {
        if let Ok(request) = std::env::var(EnvVars::UV_PYTHON) {
            if !request.is_empty() {
                python = Some(request);
            }
        }
    }

    // If `--python` / `-p` is a simple Python version request, we treat it as `--python-version`
    // for backwards compatibility. `-p` was previously aliased to `--python-version` but changed to
    // `--python` for consistency with the rest of the CLI in v0.6.0. Since we assume metadata is

View on GitHub (pinned to f1a42680ff)

When it happens

Trigger: Thrown at crates/uv/src/commands/pip/compile.rs:161 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of astral-sh/uv@f1a42680ff (2026-08-16). Data as JSON: /api/errors/790991a84f3b5bef. Report an issue: GitHub.