dagger/dagger · error

setup telemetry proxy: %w

Error message

setup telemetry proxy: %w

What it means

Wrapped by run when setupTelemetryProxy fails to start the local OTLP proxy. The proxy forwards child-process telemetry to the CLI's exporters; failure means a TCP listener or mux setup error occurred, so the run command aborts before launching the engine session.

Source

Thrown at internal/cmd/dagger/run.go:155

	return nil
}

func run(cmd *cobra.Command, args []string) error {
	ctx := cmd.Context()

	u, err := uuid.NewRandom()
	if err != nil {
		return fmt.Errorf("generate uuid: %w", err)
	}
	sessionToken := u.String()

	// Proxy OTel to the CLI and out through its locally configured exporters
	// so that it makes it to the TUI and into Cloud without having to also
	// configure the underlying command.
	otelEnv, err := setupTelemetryProxy(ctx)
	if err != nil {
		return fmt.Errorf("setup telemetry proxy: %w", err)
	}

	return withEngine(ctx, client.Params{
		SecretToken:          sessionToken,
		LoadWorkspaceModules: runLoadWorkspaceModules,
	}, func(ctx context.Context, engineClient *client.Client) error {
		sessionL, err := net.Listen("tcp", "127.0.0.1:0")
		if err != nil {
			return fmt.Errorf("session listen: %w", err)
		}
		defer sessionL.Close()

		env := os.Environ()
		sessionPort := fmt.Sprintf("%d", sessionL.Addr().(*net.TCPAddr).Port)
		env = append(env, "DAGGER_SESSION_PORT="+sessionPort)
		env = append(env, "DAGGER_SESSION_TOKEN="+sessionToken)
		env = append(env, telemetry.PropagationEnv(ctx)...)
		env = append(env, otelEnv...)

View on GitHub (pinned to 82ba2681db)

Solutions

1. Inspect the wrapped listener/serve error for port or permission issues
2. Disable the telemetry proxy if OTel forwarding is not needed
3. Free the conflicting local port and retry

When it happens

Trigger: Thrown at internal/cmd/dagger/run.go:155 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of dagger/dagger@82ba2681db (2026-09-05). Data as JSON: /api/errors/464ae30a5af5aff3. Report an issue: GitHub.