oraios/serena · error · ValueError

symbol_info_budget must be a number or null, got: {symbol_in

Error message

symbol_info_budget must be a number or null, got: {symbol_info_budget_raw}

What it means

_from_dict validates symbol_info_budget: it may be null (disabled) or a non-negative number, anything else raises ValueError. The budget controls how many symbols Serena reports per tool call, so the config parser coerces it to float and rejects negative values with a separate message.

Source

Thrown at src/serena/config/serena_config.py:613

                ) from e

        # Validate activation_command_timeout
        activation_command_timeout_raw = data.get("activation_command_timeout", 180.0)
        try:
            activation_command_timeout = float(activation_command_timeout_raw)
        except (TypeError, ValueError) as e:
            raise ValueError(f"activation_command_timeout must be a number, got: {activation_command_timeout_raw}") from e
        if activation_command_timeout <= 0:
            raise ValueError(f"activation_command_timeout must be positive, got: {activation_command_timeout}")

        # Validate symbol_info_budget
        symbol_info_budget_raw = data["symbol_info_budget"]
        symbol_info_budget = symbol_info_budget_raw
        if symbol_info_budget is not None:
            try:
                symbol_info_budget = float(symbol_info_budget_raw)
            except (TypeError, ValueError) as e:
                raise ValueError(f"symbol_info_budget must be a number or null, got: {symbol_info_budget_raw}") from e
            if symbol_info_budget < 0:
                raise ValueError(f"symbol_info_budget cannot be negative, got: {symbol_info_budget}")

        language_backend_value = data.get("language_backend")
        language_backend = LanguageBackend.from_str(language_backend_value) if language_backend_value else None

        line_ending_value = data.get("line_ending")
        line_ending = LineEnding.from_str(line_ending_value) if line_ending_value else None

        # gracefully handle user errors: incorrect use of None/empty where a list is required
        ignored_paths = data["ignored_paths"] or []
        fixed_tools = data["fixed_tools"] or []
        excluded_tools = data["excluded_tools"] or []
        included_optional_tools = data["included_optional_tools"] or []
        additional_workspace_folders = data.get("ls_additional_workspace_folders") or []

        if "base_modes" in data and data["base_modes"] is not None:
            log.warning("The base_modes setting in project.yml is deprecated and will be ignored.")

View on GitHub (pinned to 7fcbca7e62)

Solutions

Set symbol_info_budget to a non-negative number (e.g. symbol_info_budget: 50) or explicit null to disable the limit
Convert string inputs before passing: float(value) if value not in (None, 'null') else None
Ensure the key exists in project.yml (absent key raises KeyError, not this error)
Check for negative values too — a following check rejects symbol_info_budget < 0

Example fix

// before (project.yml)
symbol_info_budget: "unlimited"
// after (project.yml)
symbol_info_budget: 100

Defensive patterns

Strategy: type-guard

Validate before calling

raw = data.get("symbol_info_budget")
if raw is not None and not isinstance(raw, (int, float)):
    raise TypeError(f"symbol_info_budget must be a number or null, got {raw!r}")
if raw is not None and float(raw) < 0:
    raise ValueError(f"symbol_info_budget cannot be negative, got {raw}")

Type guard

def is_number_or_none(v) -> bool:
    return v is None or (isinstance(v, (int, float)) and not isinstance(v, bool))

Try / catch

try:
    config = ProjectConfig.load(project_root)
except ValueError as e:
    if 'symbol_info_budget' in str(e):
        logger.error("symbol_info_budget must be a number or null in project.yml: %s", e)
    raise

Prevention

Write a plain number (e.g. 100) or explicit `null` in project.yml — never words like 'unlimited'
Always include the key (missing key raises KeyError since it's read via data[...])
Convert CLI/env string inputs to float or None before passing to autogenerate
Remember negative numbers fail a separate check — clamp with max(0, value)

When it happens

Trigger: ProjectConfig.autogenerate(..., symbol_info_budget='unlimited') or a project.yml with symbol_info_budget: 'high' / true / a list; any non-numeric, non-null YAML scalar. Missing key raises KeyError instead since data['symbol_info_budget'] is accessed directly.

Common situations: Hand-editing project.yml with a descriptive word like 'default' or 'unlimited' instead of a number; passing a string from a CLI flag without conversion; YAML auto-typing surprises (e.g. `no` parsed as boolean False is fine as falsy? no — False is not None so float(False)=0.0, but 'none' string fails).

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of oraios/serena@7fcbca7e62 (2026-08-29). Data as JSON: /api/errors/2cd50d65eba50249. Report an issue: GitHub.