windows_script_interpreter

Error message

windows_script_interpreter: {interpreter:?} must be a plain executable name

What it means

The windows_script_interpreter setting names the executable that will head a generated .cmd launcher on Windows. It must be a bare executable name (ASCII alphanumerics, `.`, `_`, `-` only) because it is written directly into the launcher body; anything else (paths, flags, quoting) is rejected to avoid producing a broken or unsafe command line.

Solutions

Set windows_script_interpreter to a bare name resolvable on PATH, e.g. `python` or `node`
Move flags into the script itself or env config, not the interpreter setting
Remove path components; rely on mise-managed PATH for resolution

Example fix

// before
windows_script_interpreter = "C:/Program Files/Python/python.exe"
// after
windows_script_interpreter = "python"

Defensive patterns

Strategy: validation

Validate before calling

// bash: reject interpreter settings that aren't a plain executable name
[[ "$windows_script_interpreter" =~ ^[A-Za-z0-9._-]+$ ]] || { echo 'use a bare name like python'; exit 1; }

Type guard

// rust
fn is_plain_bin_name(s: &str) -> bool {
    !s.is_empty() && s.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '.' | '_' | '-'))
}

Prevention

Always use bare executable names resolvable via PATH for windows_script_interpreter
Pass interpreter flags via the script's shebang or env, never the interpreter setting
Avoid absolute paths and spaces in the setting

When it happens

Trigger: Setting windows_script_interpreter to a path like `C:/tools/python/python.exe`, arguments like `python -u`, or non-ASCII names, then writing a Windows script launcher (install or the launcher tests).

Common situations: Copying a full interpreter path from a working config; trying to pass interpreter flags through the setting; Unicode executable names.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

AI-assisted analysis of jdx/mise@533346cc37 (2026-09-17). Data as JSON: /api/errors/dac1bb13b7d9253e. Report an issue: GitHub.

Appendix: source

Thrown at src/backend/http.rs:1043

            );
            return None;
        }
        let file_algo = crate::backend::asset_matcher::detect_checksum_algorithm(
            &get_filename_from_url(&checksum_url),
        );
        fetch_checksum_from_file(&checksum_url, &file_algo).await
    }
}

#[cfg(any(windows, test))]
fn windows_script_launcher(script: &Path, interpreter: &str) -> Result<(PathBuf, String)> {
    ensure_plain_bin_name("windows_script_interpreter", interpreter)?;
    if interpreter.is_empty()
        || !interpreter
            .chars()
            .all(|ch| ch.is_ascii_alphanumeric() || matches!(ch, '.' | '_' | '-'))
    {
        eyre::bail!("windows_script_interpreter: {interpreter:?} must be a plain executable name");
    }
    let filename = script
        .file_name()
        .and_then(|filename| filename.to_str())
        .ok_or_else(|| eyre::eyre!("Windows script launcher requires a UTF-8 file name"))?;
    ensure_plain_bin_name("windows script", filename)?;
    if filename.is_empty()
        || !filename
            .chars()
            .all(|ch| ch.is_ascii_alphanumeric() || matches!(ch, '.' | '_' | '-'))
    {
        eyre::bail!("Windows script file name {filename:?} contains unsupported characters");
    }
    let launcher = script.with_file_name(format!("{filename}.cmd"));
    let body = format!("@echo off\r\n{interpreter} \"%~dp0{filename}\" %*\r\n");
    Ok((launcher, body))
}

View on GitHub (pinned to 533346cc37)