affaan-m/ECC · error · Error

Cannot adapt Antigravity agent ${label}: frontmatter must be

Error message

Cannot adapt Antigravity agent ${label}: frontmatter must be an object

What it means

The Antigravity agent file had frontmatter, but js-yaml loaded it into a non-object (e.g. a plain string or null, such as when the block contains only a scalar). The adapter needs a mapping of metadata keys to transform the agent.

Source

Thrown at scripts/lib/install/antigravity-agent.js:31

const MODEL_NAMES = Object.freeze({
  haiku: 'flash',
  sonnet: 'pro',
  opus: 'pro',
});

function splitFrontmatter(source, label) {
  const match = String(source || '').match(/^---\r?\n([\s\S]*?)\r?\n---\r?\n/);
  if (!match) {
    throw new Error(`Cannot adapt Antigravity agent ${label}: missing YAML frontmatter`);
  }

  // Keep YAML loading behind the transform boundary. Public help commands load
  // the installer graph without executing a transform, including in hermetic
  // packed-artifact checks where runtime dependencies are intentionally absent.
  const frontmatter = require('js-yaml').load(match[1]);
  if (!frontmatter || typeof frontmatter !== 'object' || Array.isArray(frontmatter)) {
    throw new Error(`Cannot adapt Antigravity agent ${label}: frontmatter must be an object`);
  }

  return {
    frontmatter,
    body: source.slice(match[0].length),
  };
}

function normalizeToolNames(value) {
  const names = Array.isArray(value) ? value : String(value || '').split(',');
  return [...new Set(names
    .map(name => String(name).trim())
    .filter(name => Object.hasOwn(TOOL_NAMES, name))
    .map(name => TOOL_NAMES[name]))];
}

function adaptAntigravityAgent(source, label = '<unknown>') {
  const { frontmatter, body } = splitFrontmatter(source, label);

View on GitHub (pinned to 06c5e118c4)

Solutions

1. Make the frontmatter a YAML mapping (key: value pairs), not a list or scalar.
2. Fix indentation so the frontmatter parses as an object.

When it happens

Trigger: Thrown at scripts/lib/install/antigravity-agent.js:31 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of affaan-m/ECC@06c5e118c4 (2026-08-18). Data as JSON: /api/errors/97f8849e8048cb16. Report an issue: GitHub.