Yeachan-Heo/oh-my-codex · error · Error

Unknown cancel argument: ${unsupported}

Error message

Unknown cancel argument: ${unsupported}

What it means

The cancel command accepts at most one argument, and that argument must be --force. Any other argument (or a second argument) triggers this error naming the first unsupported token. This keeps the cancellation surface intentionally minimal and prevents accidental broad or misparsed invocations.

Source

Thrown at src/cli/index.ts:8369

    assertExactSkillOwner(entry, authority, entryPath);
  }
}

interface CancellationTestFaults {
  writeFailureMode?: string;
  rollbackFailureMode?: string;
}

async function cancelModes(
  args: string[] = [],
  options: { cwd?: string; testFaults?: CancellationTestFaults } = {},
): Promise<void> {

  const cwd = options.cwd ?? process.cwd();
  const nowIso = new Date().toISOString();
  if (args.length > 1 || args.some((arg) => arg !== "--force")) {
    const unsupported = args.find((arg) => arg !== "--force") ?? args[1] ?? "";
    throw new Error(unsupported === "--all"
      ? "omx cancel --all is not supported; broad workspace cancellation requires a separate command."
      : `Unknown cancel argument: ${unsupported}`);
  }
  const force = args.length === 1;
  try {
    const writableScope = await resolveWritableStateScope(cwd);
    const baseStateDir = getBaseStateDir(cwd);
    const exactAuthority = writableScope.source === "session"
      ? await resolveExactSessionCancellationAuthority(cwd, baseStateDir, writableScope.sessionId)
      : undefined;
    const expectedOwnerIds = collectCancellationOwnerIds(baseStateDir, writableScope.sessionId);


    const loadStates = async (
      refs: ModeStateFileRef[],
      authorityRoot: string,
      ownerIds: Set<string> = expectedOwnerIds,
    ) => {

View on GitHub (pinned to 3ad79a8a6f)

Solutions

1. Remove the unsupported argument; this version supports only an optional --force
2. Check omx cancel --help for the exact accepted arguments in your version
3. Upgrade the CLI if a newer version supports the argument you're using
4. Use the dedicated command for the operation you intended

Example fix

# before
omx cancel session-123
# after
omx cancel --force

function cancelArgsValid(args: string[]): boolean {
  return args.length <= 1 && args.every((a) => a === "--force");
}

try {
  await cancel(args, options);
} catch (err) {
  if (err instanceof Error && err.message.startsWith("Unknown cancel argument")) {
    // surface usage help to the user
  } else throw err;
}

When it happens

Trigger: Running cancel with an unknown flag like --quiet, a target name as a bare argument, or two arguments (e.g. omx cancel --force --force); the find() picks the first non---force token, or args[1] when both are --force.

Common situations: Passing a session/target ID that this version doesn't accept positionally; typos in flags; scripts written against a different CLI version with richer arguments.

Related errors

• omx cancel --all is not supported; broad workspace cancellat
• --to must be ralplan or ultragoal.
• --keep-policy must be one of: score_improvement, pass_only
• Unknown capabilities subcommand: ${parsed.subcommand}
• Unknown capabilities option: ${arg}

AI-assisted analysis of Yeachan-Heo/oh-my-codex@3ad79a8a6f (2026-08-27). Data as JSON: /api/errors/926a859332fa9fe0. Report an issue: GitHub.