nodejs/node · error

must pass the parameter as --%s=value\n

Error message

must pass the parameter as --%s=value\n

What it means

For long options that take values (`--comment`, `--dictionary`, `--lgwin`, `--large_window`, `--output`, `--quality`, `--suffix`), the brotli CLI requires the `--key=value` form. If the parser finds no `=` in the token, or finds `=` as the last character (empty value), it prints the offending token and returns COMMAND_INVALID. Unlike getopt-style tools, brotli does not consume the next argv as the value.

Source

Thrown at deps/brotli/c/tools/brotli.c:596

          return COMMAND_INVALID;
        }
        command_set = BROTLI_TRUE;
        command = COMMAND_TEST_INTEGRITY;
      } else if (strcmp("verbose", arg) == 0) {
        if (params->verbosity > 0) {
          fprintf(stderr, "argument --verbose / -v already set\n");
          return COMMAND_INVALID;
        }
        params->verbosity = 1;
      } else if (strcmp("version", arg) == 0) {
        /* Don't parse further. */
        return COMMAND_VERSION;
      } else {
        /* key=value */
        const char* value = strchr(arg, '=');
        size_t key_len;
        if (!value || value[1] == 0) {
          fprintf(stderr, "must pass the parameter as --%s=value\n", arg);
          return COMMAND_INVALID;
        }
        key_len = (size_t)(value - arg);
        value++;
        if (strncmp("comment", arg, key_len) == 0) {
          if (comment_set) {
            fprintf(stderr, "comment already set\n");
            return COMMAND_INVALID;
          }
          params->comment_len = MAX_COMMENT_LEN;
          if (!ParseBase64(value, params->comment, &params->comment_len)) {
            fprintf(stderr, "invalid base64-encoded comment\n");
            return COMMAND_INVALID;
          }
          comment_set = BROTLI_TRUE;
        } else if (strncmp("dictionary", arg, key_len) == 0) {
          if (params->dictionary_path) {
            fprintf(stderr, "dictionary path already set\n");

View on GitHub (pinned to 1b2de5e052)

Solutions

1. Rewrite the flag as `--key=value`, e.g. `--lgwin=22`, `--quality=11`, `--suffix=.br`.
2. For single-letter equivalents, use the space form (`-w 22`, `-q 11`, `-S .br`) which brotli does accept.
3. In scripts, build args with the literal `=` to avoid whitespace splits.

Example fix

# before
brotli --lgwin 22 --quality 11 input.txt -o input.txt.br
# after
brotli --lgwin=22 --quality=11 input.txt -o input.txt.br

# Require --key=value form for value-taking long options.
value_opts='^(--comment|--dictionary|--lgwin|--large_window|--output|--quality|--suffix)='
for a in "$@"; do
  case "$a" in
    --comment|--dictionary|--lgwin|--large_window|--output|--quality|--suffix)
      echo "flag needs =value: $a" >&2; exit 2 ;;
    --comment=*|--dictionary=*|--lgwin=*|--large_window=*|--output=*|--quality=*|--suffix=*)
      : ;; # well-formed
    --comment*|--dictionary*|--lgwin*|--large_window*|--output*|--quality*|--suffix*)
      echo "long option must use = form: $a" >&2; exit 2 ;;
  esac
done

When it happens

Trigger: Invoking `brotli --lgwin 22 file` (space-separated), `brotli --quality=` (empty value), or `brotli --suffix .br` instead of `--suffix=.br`.

Common situations: Users transferring habits from GNU tools that accept `--flag value`; scripting that constructs args via list join without inserting `=`; typos dropping the `=`.

Related errors

• too many options passed
• quality already set
• write to standard output already set
• command already set when parsing -d
• force output overwrite already set\n

AI-assisted analysis of nodejs/node@1b2de5e052 (2026-08-13). Data as JSON: /api/errors/feb8bed1c98cfb8e. Report an issue: GitHub.