ReactiveX/rxjs · error · Error

Canonical Skill root is not a directory: ${canonicalSkillRoo

Error message

Canonical Skill root is not a directory: ${canonicalSkillRoot}

What it means

Thrown by resolveInstallation when options.canonicalSkillRoot resolves to an existing path that is not a directory. The canonical skill root is normally supplied internally by resolveCanonicalSkillRoot, so this usually indicates a broken package layout or a bad explicit override.

Source

Thrown at packages/migrate/src/skill-install.ts:184

  return manageSkillInstallation(operation, installOptions);
}

function adapterFor(harness: SkillHarness): {
  readonly adapter: SkillInstallAdapter;
  readonly localPath: string;
  readonly compatibleHarnesses: readonly SkillHarness[];
} {
  const adapter = skillHarnessAdapters[harness];
  return { adapter: adapter.adapterId, localPath: adapter.targetDirectory, compatibleHarnesses: adapter.compatibleHarnesses };
}

async function resolveInstallation(options: SkillInstallOptions): Promise<ResolvedInstallation> {
  const projectRoot = resolve(options.projectRoot);
  const canonicalProjectRoot = await realpath(projectRoot);
  if (!(await stat(canonicalProjectRoot)).isDirectory()) throw new Error(`Project root is not a directory: ${projectRoot}`);

  const canonicalSkillRoot = await realpath(resolve(options.canonicalSkillRoot));
  if (!(await stat(canonicalSkillRoot)).isDirectory()) throw new Error(`Canonical Skill root is not a directory: ${canonicalSkillRoot}`);

  const adapter = adapterFor(options.harness);
  const targetPath = resolve(projectRoot, adapter.localPath);
  assertContained(projectRoot, targetPath, 'Skill target must remain below the project root.');
  const canonicalTargetPath = await canonicalFuturePath(targetPath);
  assertContained(canonicalProjectRoot, canonicalTargetPath, 'Skill target resolves outside the project root.');
  const integrity = await inspectSkillIntegrity(canonicalSkillRoot);
  const provenance: SkillInstallProvenance = {
    ...integrity,
    installSchemaVersion: skillInstallSchemaVersion,
    adapter: adapter.adapter,
    compatibleHarnesses: adapter.compatibleHarnesses,
    targetPath: adapter.localPath.replaceAll(sep, '/'),
  };
  return {
    projectRoot,
    canonicalSkillRoot,
    targetPath,

View on GitHub (pinned to 54796b38a5)

Solutions

1. Reinstall @rxjs/migrate to restore the skill directory
2. If calling programmatically, pass the directory returned by resolveCanonicalSkillRoot
3. Verify the path with stat before invoking

Example fix

// before
manageSkillInstallation('check', { harness: 'claude', canonicalSkillRoot: './SKILL.md', projectRoot: '.' });
// after
manageSkillInstallation('check', { harness: 'claude', canonicalSkillRoot: await resolveCanonicalSkillRoot(), projectRoot: '.' });

import { stat } from 'node:fs/promises';
if (!(await stat(skillRoot)).isDirectory()) throw new TypeError(`canonicalSkillRoot not a directory: ${skillRoot}`);

const isDir = async (p: string) => (await stat(p)).isDirectory();

When it happens

Trigger: Passing a custom canonicalSkillRoot option pointing at a file; or the packaged skill/ directory being replaced by a file in a mangled install.

Common situations: Programmatic use of manageSkillInstallation with a wrong canonicalSkillRoot; corrupted @rxjs/migrate install.

Related errors

• Project root is not a directory: ${projectRoot}
• --out-dir is required with --write
• ${message}
• ${label} is not a directory: ${path}
• An output path ancestor is not a directory: ${existing}

AI-assisted analysis of ReactiveX/rxjs@54796b38a5 (2026-08-28). Data as JSON: /api/errors/d6c632b70d7f3468. Report an issue: GitHub.