coleam00/Archon · error · Error

--adopt and ${conflicts.join('/')} are mutually exclusive.

Error message

--adopt and ${conflicts.join('/')} are mutually exclusive.
  Adoption resolves its own lane: reuse the adopted worktree, or cut a fresh one from its branch.

What it means

The workflow-start preflight rejects `--adopt` when any of `--resume`, `--branch`, `--from/--from-branch`, `--base`, or `--no-worktree` is also present. Adoption resolves its own worktree lane (it reuses the adopted run's worktree or cuts a fresh one from that run's branch), so worktree-lane flags have nothing to apply to.

Source

Thrown at packages/cli/src/commands/workflow.ts:1864

  if (options.resume && options.inputs !== undefined && options.inputs.length > 0) {
    throw new Error(
      '--resume and --input are mutually exclusive.\n' +
        "  A resume replays the original invocation's inputs, recorded on the run.\n" +
        '  Drop --input to resume, or start a fresh run to supply different values.'
    );
  }

  // Between-run continuation (#2747): adoption dictates the lane itself, so the
  // lane-choosing flags are refused rather than silently overridden.
  if (options.adoptRunId !== undefined) {
    const conflicts: string[] = [];
    if (options.resume) conflicts.push('--resume');
    if (options.branchName !== undefined) conflicts.push('--branch');
    if (options.fromBranch !== undefined) conflicts.push('--from/--from-branch');
    if (options.baseBranch !== undefined) conflicts.push('--base');
    if (options.noWorktree) conflicts.push('--no-worktree');
    if (conflicts.length > 0) {
      throw new Error(
        `--adopt and ${conflicts.join('/')} are mutually exclusive.\n` +
          '  Adoption resolves its own lane: reuse the adopted worktree, or cut a fresh one from its branch.'
      );
    }
  } else if (options.supersedesRunId !== undefined && options.resume) {
    throw new Error(
      '--supersedes records a FRESH-lane rerun as replacing a prior open item; it cannot be combined with --resume.'
    );
  }

  // Per-dispatch --base override, normalized once. Wins over repo config + the
  // codebase default for both the worktree cut-from (the provider request's
  // `baseOverride` below) and the PR target / $BASE_BRANCH (executeWorkflow's
  // `baseOverride` opt). Both halves need their own channel: the `baseBranch`
  // field on either side is the codebase-default FALLBACK and ranks below repo
  // config, so routing the flag through it would silently lose to a repo that
  // sets `worktree.baseBranch`.
  const flagBase = options.baseBranch?.trim() || undefined;

View on GitHub (pinned to 0773b97458)

Solutions

  1. Remove the conflicting worktree-lane flag(s); adoption decides the lane itself.
  2. If you need explicit control over branch/base, don't use `--adopt` — start a normal fresh run with those flags.

Example fix

// before
archon workflow start code-review --adopt run_123 --base main
// after
archon workflow start code-review --adopt run_123
Defensive patterns

Strategy: validation

Validate before calling

const laneFlags = ['--resume','--branch','--from','--from-branch','--base','--no-worktree'];
if (args.includes('--adopt') && args.some(a => laneFlags.includes(a))) {
  throw new Error('--adopt resolves its own worktree lane; remove the conflicting flag.');
}

Prevention

When it happens

Trigger: `archon workflow start <name> --adopt <runId>` combined with any of `--resume`, `--branch`, `--from`, `--base`, or `--no-worktree`.

Common situations: Templated scripts that append standard worktree flags to every invocation; trying to steer the adopted run's branch with `--branch` or `--base`.

Understand the failure class

Background: "mutually exclusive" flag errors: what "can't supply both nx and xx", "--raw is not compatible with -i" and "cannot be used with" mean, and how to fix them — this error's family across 29 libraries.

Related errors

AI-assisted analysis of coleam00/Archon@0773b97458 (2026-09-01). Data as JSON: /api/errors/03d1c9869bd2190c. Report an issue: GitHub.