As already reported in #33814, #32097, #52137 the bug isn't fixed for me and the workarounds don't work either

VSCode Version: 1.26.1
OS Version: Ubuntu 16.04
Date: 2018-08-16T18:34:20.517Z
Electron: 2.0.5
Chrome: 61.0.3163.100
Node.js: 8.9.3
V8: 6.1.534.41
Architecture: x64
Shell: zsh

Steps to Reproduce:

1. Open a Git repo folder
2. Call a Git action like sync, push etc

Does this issue occur when all extensions are disabled?: Yes

I'm using ssh-agent to keep all my keys opened and enter the passwords after I boot (ssh-add ~/.ssh/id_rsa). I can use git from the terminal without any problems, but "use the terminal then" is not a valid workaround for me when a whole feature doesn't work.
I've set some configs in my ~/.ssh/config file as well

Host *
  ServerAliveInterval 60
  AddKeysToAgent yes
  IdentityFile ~/.ssh/id_rsa
Host gitlab.com
  HostName gitlab.com
  User git
Host github.com
  HostName github.com
  User git

But it still get this error when using a feature that calls a remote git action:

> git pull --tags origin master
ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists

I already tried installing ssh-askpass with sudo apt-get install ssh-askpass-gnome ssh-askpass but he asks me every single time for a password, so the ssh-agent is ignored