[Fab-user] run('git pull') fails - ssh/git issues

[Aljosa Mohorovic]

executing "run('git pull')" produces:
---
[host] out: Initialized empty Git repository in
/var/www/wsgi/<PROJECT_NAME>/tmp/.git/
[host] err: Permission denied, please try again.
[host] err: Permission denied, please try again.
[host] err: Permission denied (publickey,password).
[host] err: fatal: The remote end hung up unexpectedly
---

env.user is owner of /var/www/wsgi/<PROJECT_NAME>/ so i don't think
it's filesystem permissions issue.
i think this happens because ssh-agent is not available for fabric ssh
session so git fails because it can't authenticate when pulling.
any tips on how i could resolve this? maybe i'm missing something obvious?

Aljosa Mohorovic