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set_trace() only works the first time

See original GitHub issue

The breakpoint (as in import web_pdb; web_pdb.set_trace()) works fine for the first time. But once the debugger session is ended (e.g. by typing c and pressing enter), it won’t stop again until the dev server is restarted. By “won’t stop” I mean the breakpoint no longer works.

I’m using Django==1.11.22 and web-pdb==1.5.1 in a Docker container. The breakpoint was inserted in the beginning of a view function.

def view_func(request):
    import web_pdb; web_pdb.set_trace()
    ...

Issue Analytics

State:
Created 4 years ago
Comments:10 (7 by maintainers)

Top GitHub Comments

1reaction

maiamcccommented, Mar 6, 2020

Hey folks, I spent this afternoon poking into this, and I think it is not a container issue, but rather a webpdb-and-threads issue. I was able to reproduce the issue locally with this toy flask app.

As far as I can tell, when webpdb exits due to a thread closing (which in most Python webserver frameworks is going to happen at the end of any web request), it leaves out a bit of cleanup; whenever the set_trace() command is hit subsequently, webpdb thinks that it’s still running (because of the neglected cleanup step from before) and so doesn’t refresh the web console connection, so the debugger doesn’t work.

Opening a PR now.

0reactions

romanvmcommented, Sep 10, 2020

Closing this because of no further feedback.

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