Don't use `defer` in eth2_network to avoid https://github.com/nim-lang/Nim/issues/13899

beacon_chain/eth2_network.nim

@@ -392,14 +392,14 @@ proc sendNotificationMsg(peer: Peer, protocolId: string, requestBytes: Bytes) {.
     raise newException(TransmissionError, "Failed to open LibP2P stream")
 
   let stream = streamFut.read
-  defer:
-    await safeClose(stream)
-
+  try:
     var s = memoryOutput()
     s.appendVarint requestBytes.len.uint64
     s.append requestBytes
     let bytes = s.getOutput
     await stream.write(bytes)
+  finally:
+    await safeClose(stream)
 
 # TODO There is too much duplication in the responder functions, but
 # I hope to reduce this when I increse the reliance on output streams.
@@ -442,9 +442,7 @@ proc makeEth2Request(peer: Peer, protocolId: string, requestBytes: Bytes,
     return none(ResponseMsg)
 
   let stream = streamFut.read
-  defer:
-    await safeClose(stream)
-
+  try:
     # Send the request
     var s = memoryOutput()
     s.appendVarint requestBytes.len.uint64
@@ -454,6 +452,8 @@ proc makeEth2Request(peer: Peer, protocolId: string, requestBytes: Bytes,
 
     # Read the response
     return await stream.readResponse(ResponseMsg, deadline)
+  finally:
+    await safeClose(stream)
 
 proc init*[MsgType](T: type Responder[MsgType],
                     peer: Peer, conn: Connection): T =
@@ -546,9 +546,7 @@ proc handleIncomingStream(network: Eth2Node, conn: Connection,
 
   handleIncomingPeer(peer)
 
-  defer:
-    await safeClose(conn)
-
+  try:
     let
       deadline = sleepAsync RESP_TIMEOUT
       msgBytes = await readMsgBytes(conn, false, deadline)
@@ -577,6 +575,8 @@ proc handleIncomingStream(network: Eth2Node, conn: Connection,
       await callUserHandler(peer, conn, msg)
     except CatchableError as err:
       await sendErrorResponse(peer, conn, ServerError, err.msg)
+  finally:
+    await safeClose(conn)
 
 proc handleOutgoingPeer*(peer: Peer): Future[void] {.async.} =
   let network = peer.network