Skip spec broken since a66bc2c011

This has not worked since the merge https://travis-ci.org/ruby/ruby/jobs/538438184

spec/ruby/library/socket/socket/tcp_server_loop_spec.rb

@@ -19,34 +19,38 @@ describe 'Socket.tcp_server_loop' do
       @client.close
     end
 
-    it 'yields a Socket and an Addrinfo' do
-      @sock, addr = nil
+    # Not working since ruby/ruby a66bc2c01194a9c017c874a30db5b3b6bd95e966
+    # https://travis-ci.org/ruby/ruby/jobs/538438184
+    platform_is_not :darwin do
+      it 'yields a Socket and an Addrinfo' do
+        @sock, addr = nil
 
-      thread = Thread.new do
-        Socket.tcp_server_loop('127.0.0.1', @port) do |socket, addrinfo|
-          @sock = socket
-          addr = addrinfo
+        thread = Thread.new do
+          Socket.tcp_server_loop('127.0.0.1', @port) do |socket, addrinfo|
+            @sock = socket
+            addr = addrinfo
 
-          break
+            break
+          end
         end
-      end
 
-      SocketSpecs.loop_with_timeout do
-        begin
-          @client.connect(Socket.sockaddr_in(@port, '127.0.0.1'))
-        rescue SystemCallError
-          sleep 0.01
-          :retry
+        SocketSpecs.loop_with_timeout do
+          begin
+            @client.connect(Socket.sockaddr_in(@port, '127.0.0.1'))
+          rescue SystemCallError
+            sleep 0.01
+            :retry
+          end
         end
+
+        # At this point the connection has been set up but the thread may not yet
+        # have returned, thus we'll need to wait a little longer for it to
+        # complete.
+        thread.join(2)
+
+        @sock.should be_an_instance_of(Socket)
+        addr.should be_an_instance_of(Addrinfo)
       end
-
-      # At this point the connection has been set up but the thread may not yet
-      # have returned, thus we'll need to wait a little longer for it to
-      # complete.
-      thread.join(2)
-
-      @sock.should be_an_instance_of(Socket)
-      addr.should be_an_instance_of(Addrinfo)
     end
   end
 end