patch 8.0.1293: setting a breakpoint in the terminal debugger sometimes fails commit https://github.com/vim/vim/commit/60e73f2acc890f07056fa1bea8dbe89d26918b3e Author: Bram Moolenaar <Bram@vim.org> Date: Sun Nov 12 18:02:06 2017 +0100 patch 8.0.1293: setting a breakpoint in the terminal debugger sometimes fails Problem: Setting a breakpoint in the terminal debugger sometimes fails. Solution: Interrupt the program if needed. Set the interface to async.

#!/usr/bin/python
#
# Program that writes a number to stdout repeatedly
#
# This requires Python 2.6 or later.

from __future__ import print_function
import sys
import time

if __name__ == "__main__":

    done = 0
    while done < 10:
        done = done + 1
        print(done)
        sys.stdout.flush()
        time.sleep(0.05)  # sleep 50 msec