From 00a8a6867115cec3bbc89623fd19551a9711a72e Mon Sep 17 00:00:00 2001
From: Zahary Karadjov <zahary@gmail.com>
Date: Fri, 9 Oct 2020 16:37:12 +0300
Subject: [PATCH] Address #1695

Better error messages when the beacon node is asked to listen on a
reserved port (0) or an already taken one.
---
 beacon_chain/eth2_network.nim | 14 ++++++++++++--
 vendor/nim-confutils          |  2 +-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/beacon_chain/eth2_network.nim b/beacon_chain/eth2_network.nim
index b7020a5ab..bf0ac57b4 100644
--- a/beacon_chain/eth2_network.nim
+++ b/beacon_chain/eth2_network.nim
@@ -961,8 +961,18 @@ template publicKey*(node: Eth2Node): keys.PublicKey =
 
 proc startListening*(node: Eth2Node) {.async.} =
   if node.discoveryEnabled:
-    node.discovery.open()
-  node.libp2pTransportLoops = await node.switch.start()
+    try:
+       node.discovery.open()
+    except CatchableError as err:
+      fatal "Failed to start discovery service. UDP port may be already in use"
+      quit 1
+
+  try:
+    node.libp2pTransportLoops = await node.switch.start()
+  except CatchableError:
+    fatal "Failed to start LibP2P transport. TCP port may be already in use"
+    quit 1
+
   await node.pubsub.start()
 
 proc start*(node: Eth2Node) {.async.} =
diff --git a/vendor/nim-confutils b/vendor/nim-confutils
index 5c81aab54..5d8d1ea64 160000
--- a/vendor/nim-confutils
+++ b/vendor/nim-confutils
@@ -1 +1 @@
-Subproject commit 5c81aab54d00bb4cc0921fc9d3ace828b1fcc09f
+Subproject commit 5d8d1ea648884a460518e7819be2d406e3a4ab0f