Could not unlock ssh private key. Wrong password or password not available for cron. Reopened.

[casimir7]

This is the same issue as #1198. I reopen it here following advice by @buhtz.

Symptom:
When trying to access a(n encrypted) snapshot directory via ssh, the ssh key cannot be unlocked despite giving the correct password. The exact error message is the one in the title.

Things I have tried so far:

• Re-installing BiT and starting with a fresh configuration did not solve the problem.
• Checking that ssh-add /home/$user/.ssh./id_rsa works and that ssh-add -l lists the added key.
• Checked that I can ssh into the remote location that BiT cannot access.

Information requested by @buhtz
I run BiT in normal user mode, not in root mode (which always worked until now).
ls -l gives the following permission info on my keys:

-rw-------. 1 $user $group 2675 Sep  2  2022 id_rsa
-rw-r--r--. 1 $user $group  585 Sep  2  2022 id_rsa.pub

Thanks for your time!

[TriplEight]

Moreover, this prevents UI from opening. (also it dumps core)

Repro with screenshots

1. run backintime-qt any way
2. Fill the passphrase
   .
3. Then nothing seemingly happens, only these processes (I assume this was the automatic part from https://backintime.readthedocs.io/en/latest/settings.html#ssh). The second process reappears some times, but UI won't ever appear. Relaunching BIT won't help.
4. Only upon killing the first process you will get these windows:
   
   And then UI finally appears.

But the bug remains. Changing the keys (trying new ones too) won't help, it will produce the windows from p1 and p4.

[buhtz]

Sorry guys, I am not able to reproduce this. You have to help me here with it.
Please provide full and detailed steps on a fresh VM how to reproduce this problem.