Setting breakpoints in another thread from PDB shell

Question

When I have to debug a Python program, I generally use the interactive shell of PDB :

python -m pdb <my script>

And then set my breakpoints like this :

(Pdb) b <file>:<line>

The problem is that PDB will not break if the breakpoints are in a thread other than the main thread. For instance, in the following script :

import threading

event_quit = threading.Event()

class myThread (threading.Thread):

    def __init__(self):
        threading.Thread.__init__(self)

    def run(self):
        print("myThread start")
        print("Breakpoint here")
        print("myThread end")
        event_quit.set()

thread = myThread()
thread.start()
event_quit.wait()

PDB will not break if I set a breakpoint on print("Breakpoint here").

The solution suggested here is to put a pdb.set_trace() where I want to break in the code , instead of setting breakpoints through the interactive shell.

I find that solution a bit clumsy (requires you to open and edit the file you want to debug) and even potentially dangerous (can cause mayhem if a pdb.set_trace() is somehow left in production code).

Is there any way to debug multithreaded programs with PDB, without editing the files and using only the interactive shell ?

Setting breakpoints in another thread from PDB shell

0 Answers0