mikefarah/yq · error

'i' is not a valid option for match. To ignore case, use an…

Error message

'i' is not a valid option for match. To ignore case, use an expression like match("(?i)cat")

What it means

extractMatchArguments parses the optional params string of match/capture/test (e.g. match(exp; params)). After stripping 'g' (global), any remaining 'i' is explicitly rejected: Go's regexp supports inline case-insensitive flags, so the canonical fix the error prescribes is to embed (?i) in the pattern rather than pass an 'i' param.

Solutions

1. Use an inline flag in the pattern: match("(?i)cat")
2. Keep 'g' if you need all matches: match("(?i)cat"; "g")
3. Remove 'i' from the params argument entirely

When it happens

Trigger: Thrown at pkg/yqlib/operator_strings.go:410 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of mikefarah/yq@8b5af0694b (2026-09-05). Data as JSON: /api/errors/1e22bcde3c9a45e9. Report an issue: GitHub.

Appendix: source

Thrown at pkg/yqlib/operator_strings.go:410

	// we got given parameters e.g. match(exp; params)
	if expressionNode.RHS.Operation.OperationType == blockOpType {
		block := expressionNode.RHS
		regExExpNode = block.LHS
		replacementNodes, err := d.GetMatchingNodes(context, block.RHS)
		if err != nil {
			return nil, matchPrefs, err
		}
		paramText := ""
		if replacementNodes.MatchingNodes.Front() != nil {
			paramText = replacementNodes.MatchingNodes.Front().Value.(*CandidateNode).Value
		}
		if strings.Contains(paramText, "g") {
			paramText = strings.ReplaceAll(paramText, "g", "")
			matchPrefs.Global = true
		}
		if strings.Contains(paramText, "i") {
			return nil, matchPrefs, fmt.Errorf(`'i' is not a valid option for match. To ignore case, use an expression like match("(?i)cat")`)
		}
		if len(paramText) > 0 {
			return nil, matchPrefs, fmt.Errorf(`unrecognised match params '%v', please see docs at https://mikefarah.gitbook.io/yq/operators/string-operators`, paramText)
		}
	}

	regExNodes, err := d.GetMatchingNodes(context.ReadOnlyClone(), regExExpNode)
	if err != nil {
		return nil, matchPrefs, err
	}
	log.Debug(NodesToString(regExNodes.MatchingNodes))
	regExStr := ""
	if regExNodes.MatchingNodes.Front() != nil {
		regExStr = regExNodes.MatchingNodes.Front().Value.(*CandidateNode).Value
	}
	log.Debugf("regEx %v", regExStr)
	regEx, err := regexp.Compile(regExStr)
	return regEx, matchPrefs, err

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