What causes "unknown mode {}" in Morganamilo/paru?

Use only the characters a, r, p (e.g. `Mode = arp` for all modes)

unknown mode

Error message

unknown mode {}

What it means

`Mode::from_str` builds a bitmask mode from a character string; any character other than 'a' (AUR), 'r' (repo), or 'p' (pkgbuild) causes a bail with 'unknown mode {}'. The full input string is reported even though the offending char caused it.

Solutions

Use only the characters a, r, p (e.g. `Mode = arp` for all modes)
Remove the invalid character from the mode string
Check the docs: the mode string is a set of initials, not words

Example fix

// before
Mode = aur
// after
Mode = a  // or "ar" for aur+repo

Defensive patterns

Strategy: validation

Validate before calling

function validate_mode(input: string): string | null {
  return /^[arp]*$/.test(input) ? null : `unknown mode '${input}': only chars a, r, p are allowed`;
}

Type guard

function isValidMode(v: string): v is '' | 'a' | 'r' | 'p' | 'ar' | 'ap' | 'rp' | 'arp' {
  return /^[arp]*$/.test(v);
}

Try / catch

match Mode::from_str(input) {
    Err(e) if e.to_string().contains("unknown mode") => {
        eprintln!("{} — use initials: a=AUR, r=repo, p=pkgbuild (e.g. Mode = arp)", e);
        std::process::exit(1);
    }
    Err(e) => return Err(e),
    Ok(m) => apply(m),
}

Prevention

Remember Mode takes initials (a/r/p), not full words like 'aur'
Sanitize the mode string from environment/config before parsing
Prefer the explicit single-char form in shared configs

When it happens

Trigger: Setting a mode option to a string containing invalid characters, e.g. `Mode = abc` ('b' is invalid), `Mode = aur` (full word instead of initials), or `Mode = arz`.

Common situations: Users writing 'aur'/'repo' instead of the single letters a/r/p in paru.conf; typos in the mode string; copying mode values from other tools.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of Morganamilo/paru@9ac3578807 (2026-09-12). Data as JSON: /api/errors/54367f6f34b5a5cb. Report an issue: GitHub.

Appendix: source

Thrown at src/config.rs:332

}

impl FromStr for Mode {
    type Err = Error;

    fn from_str(input: &str) -> Result<Self> {
        let mode = match input {
            "all" => Mode::all(),
            "aur" => Mode::AUR,
            "repo" => Mode::REPO,
            "pkgbuilds" => Mode::PKGBUILD,
            _ => {
                let mut mode = Mode::empty();
                for c in input.chars() {
                    match c {
                        'a' => mode |= Mode::AUR,
                        'r' => mode |= Mode::REPO,
                        'p' => mode |= Mode::PKGBUILD,
                        _ => bail!(tr!("unknown mode {}", input)),
                    }
                }
                mode
            }
        };
        Ok(mode)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum YesNoAll {
    Yes,
    No,
    All,
}

impl ConfigEnum for YesNoAll {
    const VALUE_LOOKUP: ConfigEnumValues<Self> =

View on GitHub (pinned to 9ac3578807)