Django simulate user connected through command line
Before you start anything, set up an environment where you are not working with the live data or production environment.
Now that you've done that you have a few options.

Use the logs

The logs should give you more than enough details to get started, look at the method parameters, what error you get, where it occurs, users locale, etc. etc.

Use a copy of the live data for your testing

Take one of the users and change the password for that user in the console, then go nuts in the test environment. Beware of any data protection laws your server may be bound by when doing this

Talk to your users

Just be honest, tell your user you're looking into an issue and see if they are able to help at all
I have a lot of client who can connect successfully with login + password and did a lot of things without any problems. But I have 5 clients who managed to do strange things and now they have some problems when they go to some URLs.
Of course I dont have their password (and I dont want them). So I need a way to login like if I were them, five times, to see what's happening with their account. I may have to do this again many times in the future. I didn't find anything on google which could allow me via command line or whatever to login as a specific user easily.
Is there something around like this?