work-around an issue with using chronicles logScopes inside async procs

eth_p2p/kademlia.nim

@@ -14,6 +14,9 @@ import asyncdispatch2, eth_keys, stint, nimcrypto, chronicles, enode
 
 export sets # TODO: This should not be needed, but compilation fails otherwise
 
+template dbg(name: string, args: varargs[untyped]) =
+  chronicles.debug(name, topic = "discovery", args)
+
 logScope:
   topic = "discovery"
 
@@ -322,7 +325,7 @@ proc bond(k: KademliaProtocol, n: Node): Future[bool] {.async.} =
   let token = k.ping(n)
   let gotPong = await k.waitPong(n, token)
   if not gotPong:
-    debug "bonding failed, didn't receive pong from ", n
+    dbg "bonding failed, didn't receive pong from ", n
     # Drop the failing node and schedule a populateNotFullBuckets() call to try and
     # fill its spot.
     k.routing.removeNode(n)
@@ -335,7 +338,7 @@ proc bond(k: KademliaProtocol, n: Node): Future[bool] {.async.} =
   discard await k.waitPing(n)
 
   echo "bonding completed successfully with"
-  debug "bonding completed successfully with ", n
+  dbg "bonding completed successfully with ", n
   k.updateRoutingTable(n)
   return true
 
@@ -356,7 +359,7 @@ proc lookup*(k: KademliaProtocol, nodeId: NodeId): Future[seq[Node]] {.async.} =
     k.wire.sendFindNode(remote, nodeId)
     var candidates = await k.waitNeighbours(remote)
     if candidates.len == 0:
-      debug "got no candidates, returning ", "from" = remote
+      dbg "got no candidates, returning ", "from" = remote
       result = candidates
     else:
       # The following line:
@@ -365,12 +368,12 @@ proc lookup*(k: KademliaProtocol, nodeId: NodeId): Future[seq[Node]] {.async.} =
       # 2. Removes all previously seen nodes from candidates
       # 3. Deduplicates candidates
       candidates.keepItIf(not nodesSeen.containsOrIncl(it))
-      debug "got new candidates", count = candidates.len
+      dbg "got new candidates", count = candidates.len
       let bonded = await all(candidates.mapIt(k.bond(it)))
       for i in 0 ..< bonded.len:
         if not bonded[i]: candidates[i] = nil
       candidates.keepItIf(not it.isNil)
-      debug "bonded with candidates", count = candidates.len
+      dbg "bonded with candidates", count = candidates.len
       result = candidates
 
   proc excludeIfAsked(nodes: seq[Node]): seq[Node] =
@@ -378,10 +381,10 @@ proc lookup*(k: KademliaProtocol, nodeId: NodeId): Future[seq[Node]] {.async.} =
     sortByDistance(result, nodeId, FIND_CONCURRENCY)
 
   var closest = k.routing.neighbours(nodeId)
-  debug "starting lookup; initial neighbours: ", closest
+  dbg "starting lookup; initial neighbours: ", closest
   var nodesToAsk = excludeIfAsked(closest)
   while nodesToAsk.len != 0:
-    debug "node lookup; querying ", nodesToAsk
+    dbg "node lookup; querying ", nodesToAsk
     nodesAsked.incl(nodesToAsk.toSet())
     let results = await all(nodesToAsk.mapIt(findNode(nodeId, it)))
     for candidates in results:
@@ -410,14 +413,14 @@ proc bootstrap*(k: KademliaProtocol, bootstrapNodes: seq[Node]) {.async.} =
   discard await k.lookupRandom()
 
 proc recvPong*(k: KademliaProtocol, n: Node, token: seq[byte]) =
-  debug "<<< pong", "from" = n
+  dbg "<<< pong", "from" = n
   let pingid = token & @(n.node.pubkey.data)
   var future: Future[bool]
   if k.pongFutures.take(pingid, future):
     future.complete(true)
 
 proc recvPing*(k: KademliaProtocol, n: Node, msgHash: any) =
-  debug "<<< ping", "from" = n
+  dbg "<<< ping", "from" = n
   k.updateRoutingTable(n)
   k.wire.sendPong(n, msgHash)
 
@@ -432,19 +435,19 @@ proc recvNeighbours*(k: KademliaProtocol, remote: Node, neighbours: seq[Node]) =
   ## done as part of node lookup, so the actual processing is left to the callback from
   ## neighbours_callbacks, which is added (and removed after it's done or timed out) in
   ## wait_neighbours().
-  debug "<<< neighbours", "from" = remote, neighbours
+  dbg "<<< neighbours", "from" = remote, neighbours
   let cb = k.neighboursCallbacks.getOrDefault(remote)
   if not cb.isNil:
     cb(neighbours)
   else:
-    debug "unexpected neighbours, probably came too late", "from" = remote
+    dbg "unexpected neighbours, probably came too late", "from" = remote
 
 proc recvFindNode*(k: KademliaProtocol, remote: Node, nodeId: NodeId) =
   if remote notin k.routing:
     # FIXME: This is not correct; a node we've bonded before may have become unavailable
     # and thus removed from self.routing, but once it's back online we should accept
     # find_nodes from them.
-    debug "Ignoring find_node request from unknown node ", remote
+    dbg "Ignoring find_node request from unknown node ", remote
     return
   k.updateRoutingTable(remote)
   var found = k.routing.neighbours(nodeId)