kovidgoyal/kitty · error

Failed to parse rg help output line: %s

Error message

Failed to parse rg help output line: %s

What it means

While parsing `rg --help` output, a line in the OPTIONS section looked like an option line but no long option name (like --text) could be extracted from it. The parser found flags/aliases but zero long names on that line.

Source

Thrown at kittens/hyperlinked_grep/main.go:61

		if options_started {
			s := strings.TrimLeft(line, " ")
			indent := len(line) - len(s)
			if indent < 8 && indent > 0 {
				expecting_arg := strings.Contains(s, "=")
				single_letter_aliases := make([]string, 0, 1)
				long_option_names := make([]string, 0, 1)
				for x := range strings.SplitSeq(s, ",") {
					x = strings.TrimSpace(x)
					if strings.HasPrefix(x, "--") {
						lon, _, _ := strings.Cut(x[2:], "=")
						long_option_names = append(long_option_names, lon)
					} else if strings.HasPrefix(x, "-") {
						son, _, _ := strings.Cut(x[1:], " ")
						single_letter_aliases = append(single_letter_aliases, son)
					}
				}
				if len(long_option_names) == 0 {
					err = fmt.Errorf("Failed to parse rg help output line: %s", line)
					return
				}
				for _, x := range single_letter_aliases {
					alias_map[x] = long_option_names[0]
				}
				for _, x := range long_option_names[1:] {
					alias_map[x] = long_option_names[0]
				}
				expecting_args[long_option_names[0]] = expecting_arg
			}
		} else {
			if strings.HasSuffix(line, "OPTIONS:") {
				options_started = true
			}
		}
	}
	if len(expecting_args) == 0 || len(alias_map) == 0 {
		err = fmt.Errorf("Failed to parse rg help output, could not find any options")

View on GitHub (pinned to 6d5d0c4406)

Solutions

1. Pin/use a ripgrep version known to work with your kitty version (update kitty to match your rg)
2. Set LC_ALL=C so rg help output is not localized
3. If wrapping rg in a script, ensure passthrough of unmodified --help output

Example fix

# before
LC_ALL=de_DE.UTF-8 kitty +kitten hyperlinked_grep foo
# after
LC_ALL=C kitty +kitten hyperlinked_grep foo

if out, err := exec.Command("rg","--help").Output(); err != nil || !bytes.Contains(out, []byte("OPTIONS:")) { /* version mismatch: use plain rg */ }

When it happens

Trigger: A ripgrep version whose --help formatting differs from what the parser expects (changed indentation, wrapped lines, or new option syntax), causing a line to match the option-line heuristic without yielding a long name.

Common situations: Upgrading ripgrep to a version with reformatted help text; locale set so help output is translated; rg replaced by a wrapper/alias printing extra lines.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Failed to parse rg help output, could not find any options
• Extra characters at end of search
• not a valid file descriptor number: %#v
• %s is not valid MIME alias specification
• Failed to execute rg: %w

AI-assisted analysis of kovidgoyal/kitty@6d5d0c4406 (2026-08-27). Data as JSON: /api/errors/467354b3297b0bd2. Report an issue: GitHub.