cilium/cilium · info

expected KeyValueExpr

Error message

expected KeyValueExpr

What it means

filterRelevantConstructors is called for every KeyValueExpr in the AST and returns this sentinel when the node is not a *ast.KeyValueExpr. It is a benign filter signal, not a user-facing failure — the analyzer skips nodes it does not care about while hunting for *Vec constructor initializers.

Source

Thrown at tools/metricslint/pkg/analyzer/analyzer.go:107

	}

	nestedKV, ok := slice.Elts[0].(*ast.KeyValueExpr)
	if !ok {
		return 0, fmt.Errorf("unsupported nested varlen array type")
	}
	nestedSlice, err := getEllipsisRHSExpansion(nestedKV.Value)
	if nestedSlice == nil {
		return 0, fmt.Errorf("unsupported nested varlen array: %w", err)
	}
	return len(nestedSlice.Elts), nil
}

func filterRelevantConstructors(node ast.Node) (object, constructor string, argCount int, err error) {
	// Look for an initializer with key-value expressions that call another
	// function to initialize the field.
	kv, ok := node.(*ast.KeyValueExpr)
	if !ok {
		return "", "", 0, fmt.Errorf("expected KeyValueExpr")
	}
	key, ok := kv.Key.(*ast.Ident)
	if !ok {
		return "", "", 0, fmt.Errorf("expected Key as Ident")
	}
	call, ok := kv.Value.(*ast.CallExpr)
	if !ok {
		return "", "", 0, fmt.Errorf("expected Value as CallExpr")
	}

	// Look for a function with at least two args, where the last arg is a
	// composite literal (such as a slice). Example:
	//
	//     metric.NewCounterVec(opts, []string{...})
	if len(call.Args) < 2 {
		return "", "", 0, fmt.Errorf("expected 2+ arguments to constructor")
	}
	lastArg, ok := call.Args[len(call.Args)-1].(*ast.CompositeLit)

View on GitHub (pinned to ac7b90affa)

Solutions

1. No action needed — this error is filtered internally and the node is skipped
2. If it appears in a 'metricslint bug' report, inspect the flagged initializer and reshape it into a field: constructor(...) form

kv, ok := node.(*ast.KeyValueExpr)
if !ok {
    return // not an initializer; analyzer will skip
}

When it happens

Trigger: Any AST node reached by the Preorder walk that is not a key-value expression; in practice the walk is already restricted to KeyValueExpr, so this fires only for non-composite-literal key-value contexts (e.g. slice literals' elements that are not KV pairs).

Common situations: Code under analysis containing composite literals without keys, function calls, or other expression nodes inside literals being scanned by metricslint.

Related errors

• unknown identifier
• expected assignment statement
• unexpected RHS expression length
• expected composite literal
• unsupported ellipsis expression

AI-assisted analysis of cilium/cilium@ac7b90affa (2026-08-31). Data as JSON: /api/errors/a3196bd2137fbbf4. Report an issue: GitHub.