What causes "failed to check version : %s" in crowdsecurity/crowdsec?

Set a plain valid format_version in the parser YAML (e.g. "1.0")

failed to check version : %s

Error message

failed to check version : %s

What it means

Wraps an error from evaluating the parser format-version constraint (constraint.Satisfies) for a node in processStageFile. This is not 'version unsupported' (that path is logged and skipped) — it means the version string itself could not be checked, e.g. constraint parsing or comparison failed internally.

Source

Thrown at pkg/parser/stage.go:124

			return nil, fmt.Errorf("error decoding parsing configuration file '%s': %v", stageFile.Filename, err)
		}

		// check for empty bucket
		if node.Name == "" && node.Description == "" && node.Author == "" {
			log.Infof("Node in %s has no name, author or description. Skipping.", stageFile.Filename)
			continue
		}

		// check compat
		if node.FormatVersion == "" {
			log.Tracef("no version in %s, assuming '1.0'", node.Name)
			node.FormatVersion = "1.0"
		}

		ok, err := constraint.Satisfies(node.FormatVersion, constraint.Parser)
		if err != nil {
			return nil, fmt.Errorf("failed to check version : %s", err)
		}

		if !ok {
			log.Errorf("%s : %s doesn't satisfy parser format %s, skip", node.Name, node.FormatVersion, constraint.Parser)
			continue
		}

		node.Stage = stageFile.Stage
		// compile the node : grok pattern and expression

		err = node.compile(pctx, ectx)
		if err != nil {
			if node.Name != "" {
				return nil, fmt.Errorf("failed to compile node '%s' in '%s' : %s", node.Name, stageFile.Filename, err)
			}

			return nil, fmt.Errorf("failed to compile node in '%s' : %s", stageFile.Filename, err)
		}

View on GitHub (pinned to 909b515798)

Solutions

Set a plain valid format_version in the parser YAML (e.g. "1.0")
Check node.FormatVersion in the file — remove exotic values like 'v1.0'
If the version looks fine, report/inspect constraint.Satisfies — the failure is in the checker itself
Upgrade CrowdSec so the version-constraint library matches the hub expectations

Example fix

# before
format_version: v1.0
# after
format_version: 1.0

Defensive patterns

Strategy: validation

Validate before calling

v := strings.TrimPrefix(strings.TrimSpace(node.FormatVersion), "v")
if v == "" { v = "1.0" }
// only plain x.y / x.y.z values are known-good
if !regexp.MustCompile(`^\d+(\.\d+){0,2}$`).MatchString(v) {
    return fmt.Errorf("unsupported format_version %q", node.FormatVersion)
}

Try / catch

if _, err := constraint.Satisfies(node.FormatVersion, constraint.Parser); err != nil {
    log.Warnf("bad version in %s: %v", node.Name, err)
}

Prevention

Always use plain numeric format_version values (e.g. "1.0")
Rely on the loader's defaulting rather than inventing version strings
Upgrade CrowdSec if the constraint checker itself errors

When it happens

Trigger: Calling processStageFile (via LoadStages) when constraint.Satisfies(node.FormatVersion, constraint.Parser) returns err — malformed internal constraint or an unparsable FormatVersion reaching the checker despite the earlier defaulting to '1.0'.

Common situations: A parser file with a FormatVersion value that slips past the defaulting logic (non-empty but invalid), a corrupted constraint.Parser constant from a bad build, unusual version strings like 'v1.0' or '1.0.0-beta' that the checker cannot compare.

Related errors

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/2aaa213d5787b3da. Report an issue: GitHub.