github/spec-kit · error · ValidationError

Duplicate {singular} name '{name}' in 'provides.{section}'

Error message

Duplicate {singular} name '{name}' in 'provides.{section}'

What it means

Two entries in the same provides.templates or provides.scripts section declared the same 'name'. Duplicates are rejected because the preset resolver returns the first matching entry by name (PresetResolver._extension_manifest_declared_template), so a later duplicate would be silently unreachable while still being listed by ExtensionManifest.templates/.scripts — an invisible correctness trap, hence a hard error.

Source

Thrown at src/specify_cli/extensions/__init__.py:606

            if not isinstance(entry, dict):
                raise ValidationError(
                    f"Each entry in 'provides.{section}' must be a mapping"
                )
            if "name" not in entry or "file" not in entry:
                raise ValidationError(f"{singular.capitalize()} missing 'name' or 'file'")

            name = entry["name"]
            if not isinstance(name, str):
                raise ValidationError(
                    f"Invalid {singular} name: expected a string, got {type(name).__name__}"
                )
            if not VALID_EXTENSION_ARTIFACT_NAME_PATTERN.match(name):
                raise ValidationError(
                    f"Invalid {singular} name '{name}': "
                    "must be lowercase alphanumeric with hyphens only"
                )
            if name in seen_names:
                raise ValidationError(
                    f"Duplicate {singular} name '{name}' in 'provides.{section}'"
                )
            seen_names.add(name)

            file_value = entry["file"]
            reason = relative_extension_path_violation(file_value)
            if reason:
                label = repr(file_value) if isinstance(file_value, str) else f"for {singular} '{name}'"
                raise ValidationError(f"Invalid {singular} 'file' {label}: {reason}")

            if "description" in entry and not isinstance(entry["description"], str):
                raise ValidationError(
                    f"Invalid {singular} description for '{name}': expected a string"
                )

            if "strategy" in entry:
                raise ValidationError(
                    f"Invalid {singular} entry '{name}': 'strategy' is not authorable for "

View on GitHub (pinned to bf88c9f9a8)

Solutions

1. Give each artifact a unique name within its section, e.g. 'plan' and 'plan-extended'.
2. If the duplicate was accidental, delete one of the entries.
3. If you are merging manifests, de-duplicate by name and keep the intended 'file'.

Example fix

// before
"templates": [
  { "name": "plan", "file": "templates/plan.md" },
  { "name": "plan", "file": "templates/plan-v2.md" }
]
// after
"templates": [
  { "name": "plan", "file": "templates/plan.md" },
  { "name": "plan-v2", "file": "templates/plan-v2.md" }
]

for section in ("templates", "scripts"):
    names = [e.get("name") for e in manifest.get("provides", {}).get(section, []) if isinstance(e, dict)]
    dupes = {n for n in names if names.count(n) > 1}
    assert not dupes, f"duplicate {section} names: {dupes}"

def artifact_names_unique(provides: dict, section: str) -> bool:
    names = [e.get("name") for e in provides.get(section, []) if isinstance(e, dict)]
    return len(names) == len(set(names))

try:
    ExtensionManifest.load(path)
except ValidationError as e:
    if "Duplicate" in str(e):
        # rename or delete the later duplicate entry and retry
        ...

When it happens

Trigger: "templates": [{"name": "plan", "file": "a.md"}, {"name": "plan", "file": "b.md"}]. The seen_names set in the artifact validator triggers on the second entry during manifest validation.

Common situations: Merging two extensions' manifests by concatenation; copy-pasting an entry and forgetting to change the name; renaming one file but not its manifest name.

Related errors

• Manifest must be a YAML mapping, got {type(data).__name__}:
• Missing required field: {field}
• Invalid extension: expected a mapping, got {type(ext).__name
• Missing extension.{field}
• Invalid extension.{field}: expected a string, got {type(ext[

AI-assisted analysis of github/spec-kit@bf88c9f9a8 (2026-08-14). Data as JSON: /api/errors/bf60e9a309f61d2a. Report an issue: GitHub.