current workdir gets distorted, can't open file

Hi, running on Ubuntu 16.10, installed pudb via pip into a python3.6b2 venv.

When I use connexion to start up a webinterface, I give it the name of its config.yaml like so:

app.add_api('myconfig.yaml', argument=...)

running it in python directly or under ipdb works as expected, finding the file in the same dir as the .py file I'm, runnging. But stepping through it in pudb raises an exception at that point:

FileNotFoundError: '[...]/venv3/bin/myconfig.yaml'

So it searches for the file in the venv's bin directory?! PuDB seems to mess up the current working directory of the script running.

Start by reproducing the issue with PuDB and the reported app.add_api('myconfig.yaml') entry point, comparing it with direct Python or ipdb execution. Trace how the current working directory or relative path is resolved; done means myconfig.yaml is found beside the running .py file instead of under venv3/bin.

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