github/spec-kit · error · PresetValidationError

Manifest must be a YAML mapping, got {type(data).__name__}:

Error message

Manifest must be a YAML mapping, got {type(data).__name__}: {path}

What it means

Error "Manifest must be a YAML mapping, got {type(data).__name__}: {path}" thrown in github/spec-kit.

Source

Thrown at src/specify_cli/presets/__init__.py:300

    def _load_yaml(self, path: Path) -> dict:
        """Load YAML file safely."""
        try:
            with open(path, 'r', encoding='utf-8') as f:
                data = yaml.safe_load(f)
        except yaml.YAMLError as e:
            raise PresetValidationError(f"Invalid YAML in {path}: {e}")
        except FileNotFoundError:
            raise PresetValidationError(f"Manifest not found: {path}")
        except UnicodeDecodeError as e:
            raise PresetValidationError(
                f"Manifest is not valid UTF-8: {path} ({e.reason} at byte {e.start})"
            )
        except OSError as e:
            raise PresetValidationError(f"Could not read manifest {path}: {e}")
        if data is None:
            return {}
        if not isinstance(data, dict):
            raise PresetValidationError(
                f"Manifest must be a YAML mapping, got {type(data).__name__}: {path}"
            )
        return data

    def _validate(self):
        """Validate manifest structure and required fields."""
        # Check required top-level fields
        for field in self.REQUIRED_FIELDS:
            if field not in self.data:
                raise PresetValidationError(f"Missing required field: {field}")

        # Validate schema version
        if self.data["schema_version"] != self.SCHEMA_VERSION:
            raise PresetValidationError(
                f"Unsupported schema version: {self.data['schema_version']} "
                f"(expected {self.SCHEMA_VERSION})"
            )

View on GitHub (pinned to bf88c9f9a8)

Solutions

1. Make the preset manifest's top level a YAML mapping.

When it happens

Trigger: Thrown at src/specify_cli/presets/__init__.py:300 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of github/spec-kit@bf88c9f9a8 (2026-08-14). Data as JSON: /api/errors/a35f47c624a48902. Report an issue: GitHub.