SigNoz/signoz · warning

ErrCodeInvalidScopeExpression

ErrCodeInvalidScopeExpression

Error message

compile scope expression %q

What it means

EvalScopeExpression compiles a maintenance-window scope expression using the expr-lang evaluator against an environment built from the alert's label set. This error means the expression string failed to compile: syntax errors, unknown operators, or type conflicts with the label-derived environment (despite AllowUndefinedVariables).

Source

Thrown at pkg/types/alertmanagertypes/expression.go:77

		// (nested wins) and flag.
		if _, isMap := env[key].(map[string]any); isMap {
			conflict = true
			continue
		}
		env[key] = value
	}
	return env, conflict
}

// EvalScopeExpression compiles and runs the expression against the provided
// labels. It returns (result, error). Callers should log the error and
// decide how to handle a failed evaluation (the maintenance muter treats a
// failure as "don't skip" so alerts pass through).
func EvalScopeExpression(expression string, lset model.LabelSet) (bool, error) {
	env, _ := ConvertLabelSetToEnv(lset)
	program, err := expr.Compile(expression, expr.Env(env), expr.AllowUndefinedVariables())
	if err != nil {
		return false, errors.Wrapf(err, errors.TypeInvalidInput, ErrCodeInvalidScopeExpression, "compile scope expression %q", expression)
	}
	output, err := expr.Run(program, env)
	if err != nil {
		return false, errors.Wrapf(err, errors.TypeInternal, ErrCodeInvalidScopeExpression, "run scope expression %q", expression)
	}
	result, ok := output.(bool)
	if !ok {
		return false, errors.Newf(errors.TypeInvalidInput, ErrCodeInvalidScopeExpression, "scope expression %q returned non-bool value %T (%v)", expression, output, output)
	}
	return result, nil
}

View on GitHub (pinned to 5069bf80b0)

Solutions

1. Validate the expression syntax with expr.Compile locally before deploying config
2. Check for typos: unbalanced parens, missing operators, wrong quotes
3. Simplify the expression to label equality checks which are known-supported

Example fix

// before
expression := "env == && prod"

// after
expression := "env == \"prod\" && severity == \"critical\""

import (
  "github.com/expr-lang/expr"
  "github.com/prometheus/common/model"
)

func validateScopeExpr(expression string, lset model.LabelSet) error {
    env, _ := ConvertLabelSetToEnv(lset)
    _, err := expr.Compile(expression, expr.Env(env), expr.AllowUndefinedVariables())
    return err
}

skip, err := EvalScopeExpression(expr, lset)
if err != nil {
    // documented policy: treat failure as don't skip, alert passes through
    skip = false
    log.Warnw("scope eval failed", "expr", expr, "err", err)
}

When it happens

Trigger: Calling ShouldSkip / EvalScopeExpression with a malformed expression such as 'env == && prod', mismatched quotes, or an expression referencing labels whose inferred types conflict with the operation.

Common situations: Hand-editing maintenance/scope expression YAML config; upgrading versions that change allowed expression syntax; expressions written for a different evaluator dialect pasted into scope config.

Related errors

• ErrCodeInvalidResolver
• ErrCodeInvalidGatewayConfig
• invalid_input
• invalid_config
• ErrCodeInvalidConfig

AI-assisted analysis of SigNoz/signoz@5069bf80b0 (2026-08-28). Data as JSON: /api/errors/cefe25b5d9f4a090. Report an issue: GitHub.