I've been using the (LLM generated) example below as a starting point for some basic web server scripts since last year. This worked fine on 3.3, but since upgrading to 3.4, I get RuntimeError as soon as a client connects.

server = TCPServer.new('0.0.0.0', 8080)
loop do
  client = server.accept
  request = client.gets
  puts "Received request: #{request}"
  response = "HTTP/1.1 200 OK\r\n" \
             "Content-Type: text/plain\r\n" \
             "Content-Length: 13\r\n" \
             "Connection: close\r\n" \
             "\r\n" \
             "Hello, world!"
  client.write(response)
  client.close
end

With conf.enable_debug on current master:

mrbgems/mruby-socket/mrblib/socket.rb:285:in accept: RuntimeError

And after removing the rescue block in TCPServer#accept:

mrbgems/mruby-socket/mrblib/socket.rb:257:in initialize: private method 'initialize' called for TCPSocket (NoMethodError)