usock_pdb.py

from socket import socket, AF_UNIX
from pdb import Pdb
from os import unlink, getuid, getpid, chmod
from signal import signal, SIGUSR1

def rtrace(signum, frame):
    spath = '/tmp/{:d}.pdb.{:d}'.format(getuid(), getpid())
    with socket(AF_UNIX) as sock:
        chmod(sock.fileno(), 0o700)
        sock.bind(spath)
        sock.listen(1)
        conn, addr = sock.accept()
        fd = conn.makefile('rw')
        dbgr = Pdb(stdin=fd, stdout=fd)
        dbgr.set_trace()
    unlink(spath)

signal(SIGUSR1, rtrace)