crowdsecurity/crowdsec · error

unable to create folder '%s': %w

Error message

unable to create folder '%s': %w

What it means

installAppsecRuleCustomFrom creates the runtime appsec-rules directory (os.MkdirAll) before copying a custom rule, and wraps MkdirAll failures. It means the directory <RuntimePath>/appsec-rules/ could not be created — a filesystem-level permission or path problem, not a missing rule.

Source

Thrown at pkg/hubtest/appsecrule.go:61

		}
	}

	return nil
}

func (t *HubTestItem) installAppsecRuleCustomFrom(appsecrule string, customPath string) (bool, error) {
	// we check if its a custom appsec-rule
	customAppsecRulePath := filepath.Join(customPath, appsecrule)
	if _, err := os.Stat(customAppsecRulePath); os.IsNotExist(err) {
		return false, nil
	}

	customAppsecRulePathSplit := strings.Split(customAppsecRulePath, "/")
	customAppsecRuleName := customAppsecRulePathSplit[len(customAppsecRulePathSplit)-1]

	itemTypeDirDest := fmt.Sprintf("%s/appsec-rules/", t.RuntimePath)
	if err := os.MkdirAll(itemTypeDirDest, os.ModePerm); err != nil {
		return false, fmt.Errorf("unable to create folder '%s': %w", itemTypeDirDest, err)
	}

	customAppsecRuleDest := fmt.Sprintf("%s/appsec-rules/%s", t.RuntimePath, customAppsecRuleName)
	if err := Copy(customAppsecRulePath, customAppsecRuleDest); err != nil {
		return false, fmt.Errorf("unable to copy appsec-rule from '%s' to '%s': %w", customAppsecRulePath, customAppsecRuleDest, err)
	}

	return true, nil
}

func (t *HubTestItem) installAppsecRuleCustom(appsecrule string) error {
	for _, customPath := range t.CustomItemsLocation {
		found, err := t.installAppsecRuleCustomFrom(appsecrule, customPath)
		if err != nil {
			return err
		}

		if found {

View on GitHub (pinned to 909b515798)

Solutions

1. Check ownership/permissions of RuntimePath and create the appsec-rules directory with adequate rights (sudo/chown)
2. Ensure no regular file named 'appsec-rules' is shadowing the directory path
3. Point RuntimePath at a writable location for the test run

Example fix

# before
mkdir: cannot create directory '/etc/crowdsec/appsec-rules/': Permission denied
# after
sudo mkdir -p /etc/crowdsec/appsec-rules && sudo chown -R $USER /etc/crowdsec/appsec-rules

dest := filepath.Join(t.RuntimePath, "appsec-rules")
if fi, err := os.Stat(dest); err == nil && !fi.IsDir() {
	return fmt.Errorf("%s exists but is not a directory", dest)
}
if err := os.MkdirAll(dest, 0o755); err != nil {
	return fmt.Errorf("cannot create %s: %w", dest, err)
}

When it happens

Trigger: installAppsecRuleCustom → installAppsecRuleCustomFrom when the custom rule file exists under one of CustomItemsLocation but os.MkdirAll("<RuntimePath>/appsec-rules/", os.ModePerm) returns an error (EACCES, ENOENT ancestor with restricted rights, read-only fs, path component is a file).

Common situations: RuntimePath points inside a root-owned tree while tests run unprivileged; a file named 'appsec-rules' already exists at that path; tests executed on a read-only CI workspace.

Understand the failure class

Background: mkdir permission denied (EACCES): failed to create directory errors explained — this error's family across 32 libraries.

Related errors

• while creating directories for %s: %w
• while creating %s: %w
• while creating %s: %w
• while creating data dir: %w
• unable to create directory '%s': %w

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/5d627b37b651a5d9. Report an issue: GitHub.