What causes "failed to parse: %w" in crowdsecurity/crowdsec?

Validate the datasource stanza with a YAML linter; the wrapped error names the line and problem

failed to parse: %w

Error message

failed to parse: %w

What it means

ParseSourceConfig failed to unmarshal the common datasource configuration (DataSourceCommonCfg) out of the YAML document. The goccy/go-yaml unmarshalling error is reformatted with yaml.FormatError (non-strict, no source hints) and wrapped as 'failed to parse: %w'. It fires when the document's common fields (source, labels, mode, etc.) have YAML syntax errors or type mismatches — note unmarshalling is intentionally non-strict because datasource-specific keys are collected later.

Source

Thrown at pkg/acquisition/acquisition.go:248

	if err != nil {
		return nil, err
	}

	// if there are not keys or only comments, the document will be skipped
	empty, err := csyaml.IsEmptyYAML(bytes.NewReader(yamlDoc))
	if err != nil {
		return nil, err
	}

	if empty {
		return nil, ErrEmptyYAMLDocument
	}

	var sub configuration.DataSourceCommonCfg

	// can't be strict here, the doc contains specific datasource config too but we won't collect them now.
	if err = yaml.UnmarshalWithOptions(yamlDoc, &sub); err != nil {
		return nil, fmt.Errorf("failed to parse: %w", errors.New(yaml.FormatError(err, false, false)))
	}

	parsed := &ParsedSourceConfig{}

	// report that the user did not specify a source
	if sub.Source == "" {
		parsed.SourceMissing = true
	}

	// report that the user specified a source that doesn't match with one detected from the presence of other fields
	if detectedType != "" {
		if sub.Source != "" && sub.Source != detectedType {
			parsed.SourceOverridden = sub.Source
		}

		sub.Source = detectedType
	}

View on GitHub (pinned to 909b515798)

Solutions

Validate the datasource stanza with a YAML linter; the wrapped error names the line and problem
Check for tabs instead of spaces, unquoted special characters, or wrong indentation under the datasource block
Ensure scalar fields like mode and source are plain strings, and labels is a mapping of string to string

Defensive patterns

Strategy: try-catch

When it happens

Trigger: Thrown at pkg/acquisition/acquisition.go:248 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/464da24e10f85b15. Report an issue: GitHub.