gopro is a simple and stupid protocol analyzer written in order to see what gdb sends to the serial port (or to another gdb server via tcp). I didn't manage to make socat work for me.

It turns out that it's still useful when debugging ESP8266 remotely

The main problem with this tool is that it doesn't close the socket (or quits) when the inbound http connection is dropped, and it will happily accept more incoming connections, which is fine for tcp->tcp forwarding, but it doesn't play well with serial ports. Thus, you should ctrl-c the tool after disconnecting from gdb.

usage: gopro -s :1234 -d /dev/tty.SLAB_USBtoUART -b 115200