owasp-amass/amass · error

failed to create the RDAP disk cache

Error message

failed to create the RDAP disk cache

What it means

Returned by rdapPlugin.Start when cache.NewDiskCache() returns nil, i.e. the RDAP bootstrap disk cache could not be constructed. It is a generic nil-guard on the cache constructor, so the underlying cause (filesystem or environment problem) is not captured in the error itself.

Source

Thrown at engine/plugins/api/rdap/plugin.go:75

		},
	}
}

func (rd *rdapPlugin) Name() string {
	return rd.name
}

func (rd *rdapPlugin) Start(r et.Registry) error {
	rd.log = r.Log().WithGroup("plugin").With("name", rd.name)

	outdir := config.OutputDirectory()
	if outdir == "" {
		return errors.New("failed to obtain the Amass output directory")
	}

	c := cache.NewDiskCache()
	if c == nil {
		return errors.New("failed to create the RDAP disk cache")
	}
	c.Dir = filepath.Join(outdir, ".openrdap")

	bs := &bootstrap.Client{Cache: c}
	tlsConfig := &tls.Config{InsecureSkipVerify: true}
	transport := &http.Transport{
		Proxy:           http.ProxyFromEnvironment,
		TLSClientConfig: tlsConfig,
	}
	bs.HTTP = &http.Client{
		Transport: transport,
	}
	httpClient := &http.Client{
		Transport: transport,
	}
	rd.client = &rdap.Client{
		HTTP:      httpClient,
		Bootstrap: bs,

View on GitHub (pinned to 79299dce87)

Solutions

1. Check the openrdap cache dependency version and update/rebuild
2. Verify the process can write to the default cache directory before plugin start
3. Fall back to an in-memory cache if disk cache construction fails
4. Report upstream if NewDiskCache nil-returns with valid inputs

Example fix

// before
c := cache.NewDiskCache()
// after
c := cache.NewDiskCache()
if c == nil {
    c = cache.NewMemoryCache()
}

func cacheReady(c *cache.DiskCache) bool { return c != nil }

if err := plugin.Start(registry); err != nil {
    if strings.Contains(err.Error(), "disk cache") {
        log.Warn("rdap plugin disabled: cache init failed")
        return
    }
    return err
}

When it happens

Trigger: rdapPlugin.Start calls cache.NewDiskCache() and it returns nil — e.g. the cache library fails to allocate/initialize its default configuration.

Common situations: Incompatible or broken openrdap/cache dependency version where NewDiskCache can return nil; resource/permission problems at default cache location; defective build.

Related errors

• failed to obtain the Amass output directory
• failed to create the session manager
• failed to create the API server
• zero locations found
• failed to extract the locations

AI-assisted analysis of owasp-amass/amass@79299dce87 (2026-09-06). Data as JSON: /api/errors/cc0797452fddbd01. Report an issue: GitHub.