Add host information to timeout error messages in `TCPSocket.new` and `Socket.tcp` (#15582)

This change adds host information to the error messages shown when a timeout occurs while passing timeout options to `TCPSocket.new` or `Socket.tcp`, for improved usability.
(When the `fast_fallback option` is enabled, there may be multiple possible destinations, so the host name is shown instead of an IP address.)

As part of this change, the error messages in `Addrinfo.getaddrinfo` and `Addrinfo#connect_internal`, both of which are used by `Socket.tcp`, have also been improved in the same way.

1 files changed, 5 insertions, 3 deletions

diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
index 6d04ca2483..e74eaec43a 100644
--- a/ext/socket/lib/socket.rb
+++ b/ext/socket/lib/socket.rb
@@ -62,7 +62,7 @@ class Addrinfo
           break
         when :wait_writable
           sock.wait_writable(timeout) or
-            raise Errno::ETIMEDOUT, 'user specified timeout'
+            raise Errno::ETIMEDOUT, "user specified timeout for #{self.ip_address}:#{self.ip_port}"
         end while true
       else
         sock.connect(self)
@@ -905,7 +905,9 @@ class Socket < BasicSocket
         end
       end
 
-      raise(IO::TimeoutError, 'user specified timeout') if expired?(now, user_specified_open_timeout_at)
+      if expired?(now, user_specified_open_timeout_at)
+        raise(IO::TimeoutError, "user specified timeout for #{host}:#{port}")
+      end
 
       if resolution_store.empty_addrinfos?
         if connecting_sockets.empty? && resolution_store.resolved_all_families?
@@ -918,7 +920,7 @@ class Socket < BasicSocket
 
         if (expired?(now, user_specified_resolv_timeout_at) || resolution_store.resolved_all_families?) &&
            (expired?(now, user_specified_connect_timeout_at) || connecting_sockets.empty?)
-          raise IO::TimeoutError, 'user specified timeout'
+          raise(IO::TimeoutError, "user specified timeout for #{host}:#{port}")
         end
       end
     end