CoplayDev/unity-mcp · error · ValueError

{name} must be a boolean

Error message

{name} must be a boolean

What it means

Thrown by _coerce_bool() when the value is not a bool, not 0/1 (int or float), and not a recognized truthy/falsy string ('true'/'false'/'1'/'0'/'yes'/'no'/'on'/'off', case-insensitive, trimmed). The {name} placeholder identifies which boolean option failed (e.g. srgb, readable, generate_mipmaps), surfaced via _normalize_import_settings.

Source

Thrown at Server/src/cli/commands/texture.py:242

    return value


_TRUE_STRINGS = {"true", "1", "yes", "on"}
_FALSE_STRINGS = {"false", "0", "no", "off"}


def _coerce_bool(value: Any, name: str) -> bool:
    if isinstance(value, bool):
        return value
    if isinstance(value, (int, float)) and value in (0, 1, 0.0, 1.0):
        return bool(value)
    if isinstance(value, str):
        lowered = value.strip().lower()
        if lowered in _TRUE_STRINGS:
            return True
        if lowered in _FALSE_STRINGS:
            return False
    raise ValueError(f"{name} must be a boolean")


def _normalize_import_settings(value: Any) -> dict[str, Any]:
    if value is None:
        return {}
    if isinstance(value, str):
        value = try_parse_json(value, "import_settings")
    if not isinstance(value, dict):
        raise ValueError("import_settings must be a JSON object")

    result: dict[str, Any] = {}

    if "texture_type" in value:
        result["textureType"] = _map_enum(
            value["texture_type"], _TEXTURE_TYPES)
    if "texture_shape" in value:
        result["textureShape"] = _map_enum(
            value["texture_shape"], _TEXTURE_SHAPES)

View on GitHub (pinned to c21bf496bc)

Solutions

1. Use true/false, 1/0, yes/no, or on/off for boolean import settings.
2. Double-check the value for the field named in the error message.
3. Prefer native JSON booleans (`"srgb": true`) over strings where possible.

Example fix

// before
--import-settings '{"readable":"enable"}'
// after
--import-settings '{"readable":true}'

_BOOL = {"true": True, "false": False, "1": True, "0": False, "yes": True, "no": False, "on": True, "off": False}
if isinstance(v, bool) or (isinstance(v, (int, float)) and v in (0, 1)):
    b = bool(v)
elif isinstance(v, str) and v.strip().lower() in _BOOL:
    b = _BOOL[v.strip().lower()]
else:
    raise ValueError(f"{name} must be a boolean")

def is_coerceable_bool(v) -> bool:
    if isinstance(v, bool): return True
    if isinstance(v, (int, float)) and v in (0, 1, 0.0, 1.0): return True
    return isinstance(v, str) and v.strip().lower() in {"true","false","1","0","yes","no","on","off"}

try:
    settings = _normalize_import_settings(raw)
except ValueError as e:
    print_error(str(e)); sys.exit(1)

When it happens

Trigger: Passing an import_settings boolean as an unparseable value such as `{"srgb":"yes please"}`, `{"readable":2}`, or `{"generate_mipmaps":"enable"}`. Triggered when _normalize_import_settings hits one of the snake-case boolean keys and calls _coerce_bool.

Common situations: A developer supplies a boolean field with a free-text value, an out-of-range integer, or a non-English word. Common when hand-writing the import-settings JSON without checking accepted string values.

Related errors

• import_settings must be a JSON object
• set-pixels is required
• set-pixels must be a JSON object
• set-pixels requires width and height when pixels are provide
• set-pixels width and height must be positive

AI-assisted analysis of CoplayDev/unity-mcp@c21bf496bc (2026-08-13). Data as JSON: /api/errors/debe044652a90de4. Report an issue: GitHub.