Tell mono folks why their DNS-based connect fails, and what to do about it

BasicTest/Program.cs

@@ -26,8 +26,8 @@ static void Main(string[] args)
             MassiveBulkOpsAsync(AsyncOpsQty, false, false);
         }
         static void MassiveBulkOpsAsync(int AsyncOpsQty, bool preserveOrder, bool withContinuation)
-        {
-            using (var muxer = ConnectionMultiplexer.Connect("127.0.0.1"))
+        {            
+            using (var muxer = ConnectionMultiplexer.Connect("localhost,resolvedns=1"))
             {
                 muxer.PreserveAsyncOrder = preserveOrder;
                 RedisKey key = "MBOA";

StackExchange.Redis/StackExchange/Redis/EndPointCollection.cs

@@ -67,7 +67,15 @@ protected override void InsertItem(int index, EndPoint item)
         protected override void SetItem(int index, EndPoint item)
         {
             if (item == null) throw new ArgumentNullException("item");
-            int existingIndex = IndexOf(item);
+            int existingIndex;
+            try
+            {
+                existingIndex = IndexOf(item);
+            } catch(NullReferenceException)
+            {
+                // mono has a nasty bug in DnsEndPoint.Equals; if they do bad things here: sorry, I can't help
+                existingIndex = -1;
+            }
             if (existingIndex >= 0 && existingIndex != index) throw new ArgumentException("EndPoints must be unique", "item");
             base.SetItem(index, item);
         }

StackExchange.Redis/StackExchange/Redis/SocketManager.cs

@@ -122,7 +122,17 @@ internal SocketToken BeginConnect(EndPoint endpoint, ISocketCallback callback)
             var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
             SetFastLoopbackOption(socket);
             socket.NoDelay = true;
-            socket.BeginConnect(endpoint, EndConnect, Tuple.Create(socket, callback));
+            try
+            {
+                socket.BeginConnect(endpoint, EndConnect, Tuple.Create(socket, callback));
+            } catch (NotImplementedException ex)
+            {
+                if (!(endpoint is IPEndPoint))
+                {
+                    throw new InvalidOperationException("BeginConnect failed with NotImplementedException; consider using IP endpoints, or enable ResolveDns in the configuration", ex);
+                }
+                throw;
+            }
             return new SocketToken(socket);
         }
         internal void SetFastLoopbackOption(Socket socket)

monobuild.bash

@@ -3,7 +3,7 @@ rm -rf BasicTest/bin/mono
 mkdir -p StackExchange.Redis/bin/mono
 mkdir -p BasicTest/bin/mono
 echo -e "Building StackExchange.Redis.dll ..."
-mcs -recurse:StackExchange.Redis/*.cs -out:StackExchange.Redis/bin/mono/StackExchange.Redis.dll -target:library -unsafe+ -o+ -r:System.IO.Compression.dll -d:MONO
+mcs -recurse:StackExchange.Redis/*.cs -out:StackExchange.Redis/bin/mono/StackExchange.Redis.dll -target:library -unsafe+ -o+ -r:System.IO.Compression.dll
 echo -e "Building BasicTest.exe ..."
 mcs BasicTest/Program.cs -out:BasicTest/bin/mono/BasicTest.exe -target:exe -o+ -r:StackExchange.Redis/bin/mono/StackExchange.Redis.dll
 cp StackExchange.Redis/bin/mono/*.* BasicTest/bin/mono/

monobuild.cmd

@@ -3,7 +3,7 @@
 @md StackExchange.Redis\bin\mono 1>nul 2>nul
 @md BasicTest\bin\mono 1>nul 2>nul
 @echo Building StackExchange.Redis.dll ...
-@call mcs -recurse:StackExchange.Redis\*.cs -out:StackExchange.Redis\bin\mono\StackExchange.Redis.dll -target:library -unsafe+ -o+ -r:System.IO.Compression.dll -d:MONO
+@call mcs -recurse:StackExchange.Redis\*.cs -out:StackExchange.Redis\bin\mono\StackExchange.Redis.dll -target:library -unsafe+ -o+ -r:System.IO.Compression.dll
 @echo Building BasicTest.exe ...
 @call mcs BasicTest\Program.cs -out:BasicTest\bin\mono\BasicTest.exe -target:exe -o+ -r:StackExchange.Redis\bin\mono\StackExchange.Redis.dll
 @copy StackExchange.Redis\bin\mono\*.* BasicTest\bin\mono > nul