AdguardTeam/AdGuardHome · error

got without argument

Error message

got %s without argument

What it means

A command-line option that requires a value was the last token on the command line, so the iterator next() returned no value. applyOptWithValue reports which flag is missing its argument.

Solutions

1. Append the required value after the flag: -c /path/to/config.yaml
2. Quote and default empty shell variables: -w "${WORKDIR:-/var/lib/adguardhome}"
3. Validate generated command lines in scripts before executing

Example fix

# before
./AdGuardHome -c

# after
./AdGuardHome -c /etc/adguardhome.yaml

// Ensure value-taking flags are never last:
if strings.HasPrefix(arg, "-") && i == len(args)-1 && requiresValue(arg) {
    return fmt.Errorf("flag %s needs a value", arg)
}

When it happens

Trigger: Ending argv with a value-taking flag: ./AdGuardHome -c or ./AdGuardHome --workdir with nothing after it.

Common situations: Shell scripts where a variable expands to empty (-w "$WORKDIR" with WORKDIR unset), or truncated command lines in service unit files.

Related errors

• applying option
• parsing arg at index
• parsing port
• unknown option
• action

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/eb6fe0fbe69d41aa. Report an issue: GitHub.

Appendix: source

Thrown at internal/home/options.go:453

	if err != nil {
		return o, eff, fmt.Errorf("applying option %s: %w", arg, err)
	}

	return newOpts, newEff, nil
}

// applyOptWithValue applies argument with value.   next and eff must not
// be nil.
func applyOptWithValue(
	opt cmdLineOpt,
	next func() (int, string, bool),
	o options,
	eff effect,
	arg string,
) (newOpt options, newEff effect, err error) {
	_, val, ok := next()
	if !ok {
		return o, eff, fmt.Errorf("got %s without argument", arg)
	}

	newOpts, err := opt.updateWithValue(o, val)
	if err != nil {
		return o, eff, fmt.Errorf("applying option %s: %w", arg, err)
	}

	return newOpts, eff, nil
}

// findMatchingOpt returns cmdLineOpt which matches the given arg.  ok indicates
// whether the appropriate option was found.
func findMatchingOpt(arg string) (opt cmdLineOpt, ok bool) {
	for _, opt := range cmdLineOpts {
		if argMatches(opt, arg) {
			return opt, true
		}
	}

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