Function preexec_fn

src/debugpy/launcher/debuggee.py:64–86

()

            # GraalPy does not support running code between fork and exec

            def preexec_fn():
                try:
                    # Start the debuggee in a new process group, so that the launcher can
                    # kill the entire process tree later.
                    os.setpgrp()

                    # Make the new process group the foreground group in its session, so
                    # that it can interact with the terminal. The debuggee will receive
                    # SIGTTOU when tcsetpgrp() is called, and must ignore it.
                    old_handler = signal.signal(signal.SIGTTOU, signal.SIG_IGN)
                    try:
                        tty = os.open("/dev/tty", os.O_RDWR)
                        try:
                            os.tcsetpgrp(tty, os.getpgrp())
                        finally:
                            os.close(tty)
                    finally:
                        signal.signal(signal.SIGTTOU, old_handler)
                except Exception:
                    # Not an error - /dev/tty doesn't work when there's no terminal.
                    log.swallow_exception(
                        "Failed to set up process group", level="info"
                    )

            kwargs.update(preexec_fn=preexec_fn)