ethereum/go-ethereum · error

nil TextMapPropagator configured

Error message

nil TextMapPropagator configured

What it means

WithTextMapPropagator panics when passed a nil propagator. This client option enables OpenTelemetry trace-context propagation (the traceparent header); because the client does not propagate by default, the option stores the propagator unconditionally, so a nil value is rejected as a configuration programming error at DialOptions time.

Source

Thrown at rpc/client_opt.go:109

func WithHeaders(headers http.Header) ClientOption {
	return optionFunc(func(cfg *clientConfig) {
		cfg.initHeaders()
		for k, vs := range headers {
			cfg.httpHeaders[k] = vs
		}
	})
}

// WithTextMapPropagator configures OpenTelemetry trace propagation.
// Note, by default, trace context is NOT propagated by rpc.Client.
// To enable propagation via the `traceparent` header, you must explicitly
// enable it by setting a propagator, e.g.
//
//	prop := propagation.TraceContext{}
//	c, err := rpc.DialOptions(ctx, "http://", rpc.WithTextMapPropagator(prop))
func WithTextMapPropagator(tmp propagation.TextMapPropagator) ClientOption {
	if tmp == nil {
		panic("nil TextMapPropagator configured")
	}
	return optionFunc(func(cfg *clientConfig) {
		cfg.tmprop = tmp
	})
}

// WithHTTPClient configures the http.Client used by the RPC client.
func WithHTTPClient(c *http.Client) ClientOption {
	return optionFunc(func(cfg *clientConfig) {
		cfg.httpClient = c
	})
}

// WithHTTPAuth configures HTTP request authentication. The given provider will be called
// whenever a request is made. Note that only one authentication provider can be active at
// any time.
func WithHTTPAuth(a HTTPAuth) ClientOption {
	if a == nil {

View on GitHub (pinned to 6bb0588ad8)

Solutions

1. Pass a concrete propagator, e.g. rpc.WithTextMapPropagator(propagation.TraceContext{}).
2. If tracing is optional, guard the call: only append the option when the propagator is non-nil.
3. Ensure the OpenTelemetry SDK is initialized before reading a global propagator.

Example fix

// before
var prop propagation.TextMapPropagator // nil when tracing disabled
c, err := rpc.DialOptions(ctx, url, rpc.WithTextMapPropagator(prop))

// after
var opts []rpc.ClientOption
if prop != nil {
    opts = append(opts, rpc.WithTextMapPropagator(prop))
}
c, err := rpc.DialOptions(ctx, url, opts...)

var opts []rpc.ClientOption
if prop != nil { // skip option entirely when tracing disabled
    opts = append(opts, rpc.WithTextMapPropagator(prop))
}
c, err := rpc.DialOptions(ctx, url, opts...)

When it happens

Trigger: Calling rpc.DialOptions(ctx, url, rpc.WithTextMapPropagator(nil)) or passing a propagator variable declared as var prop propagation.TextMapPropagator and never assigned.

Common situations: Making tracing optional in application config and forwarding a nil when tracing is disabled; passing an uninitialized struct field from a config struct; refactoring from a global otel.GetTextMapPropagator() that returned nil before OTel SDK initialization.

Related errors

• nil auth
• channel given to Subscribe must not be nil
• can't create multiple subscriptions with Notifier
• can't create subscription after subscribe call has returned
• can't Notify before subscription is created

AI-assisted analysis of ethereum/go-ethereum@6bb0588ad8 (2026-08-15). Data as JSON: /api/errors/bd36fa775bca307c. Report an issue: GitHub.