cli: fatal error if rpc could not be started

cmd/geth/main.go

@@ -354,7 +354,9 @@ func startEth(ctx *cli.Context, eth *eth.Ethereum) {
 	}
 	// Start auxiliary services if enabled.
 	if ctx.GlobalBool(utils.RPCEnabledFlag.Name) {
-		utils.StartRPC(eth, ctx)
+		if err := utils.StartRPC(eth, ctx); err != nil {
+			utils.Fatalf("Error starting RPC: %v", err)
+		}
 	}
 	if ctx.GlobalBool(utils.MiningEnabledFlag.Name) {
 		eth.StartMining()

cmd/utils/flags.go

@@ -330,7 +330,7 @@ func GetAccountManager(ctx *cli.Context) *accounts.Manager {
 	return accounts.NewManager(ks)
 }
 
-func StartRPC(eth *eth.Ethereum, ctx *cli.Context) {
+func StartRPC(eth *eth.Ethereum, ctx *cli.Context) error {
 	config := rpc.RpcConfig{
 		ListenAddress: ctx.GlobalString(RPCListenAddrFlag.Name),
 		ListenPort:    uint(ctx.GlobalInt(RPCPortFlag.Name)),
@@ -338,7 +338,7 @@ func StartRPC(eth *eth.Ethereum, ctx *cli.Context) {
 	}
 
 	xeth := xeth.New(eth, nil)
-	_ = rpc.Start(xeth, config)
+	return rpc.Start(xeth, config)
 }
 
 func StartPProf(ctx *cli.Context) {