Fetch stalls if credential.helper=cache is enabled

[mrazzari]

Smart-pull is stalling after I successfully authenticate.

$ git smart-pull
- Starting: smart-pull on branch 'master' -
Executing: git fetch origin
Username for 'https://github.com': mrazzari
Password for 'https://mrazzari@github.com':

I have multiple users on this Ubuntu machine.
User A gets stuck here.
But for user B, or for root, things work perfectly.

So it looks like a permissions or user config issue...

How can I debug this?
(Debug mode, verbose param, or where to add some "print" statements? etc).

[mrazzari]

So, after diffing the git configs for user A and B, this one turned out to be the problem:
credential.helper=cache --timeout=43200

I "fixed" it by removing it from my config...
git config --global --unset credential.helper

Leaving the issue open in case you want to provide a workaround / fallback / warning for this pretty common setting.