Can't login after a system upgrade using pacman -Syu on Arch

[codelast]

Hi everybody, I installed Arch Linux ARM on my Raspberry Pi model B+ and after a system upgrade yesterday using pacman -Syu, I can't login to Pi using ssh anymore. I always use root user to login and after the system upgrade, the terminal prompt "Permission denied, please try again", which I think means that my password was incorrect, but I'm so sure that my provided password is correct because I do not remember it in my head but copy it out from a file. So I was so confused and I tried following methods and they all didn't work:
(1) plug the Raspberry Pi TF card to another Ubuntu PC, edit the /etc/shadow file on the TF card, delete the password field of the root user, to make it became:
$this->bbcode_second_pass_code('', 'root::16660::::::')

and then plug the TF card back to Pi, boot Pi, theoretically, the terminal should not ask for password, but it still ask me to provide password, so you know the following story - failed to login.
(2) edit the /etc/shadow file on the TF card, edit the password field of the root user to a sha-512(Arch Linux ARM default) encrypted password "root"(the initial password of Arch Linux ARM root user), and plug the TF card back to Pi, boot Pi, when asking for password, the "root" password was still consider not right("Permission denied, please try again").

So I'm totally don't know what's wrong with my previous solution & how to recover my root user password, to let me login to Pi?

Any help is appreciated, thank you!

[moonman]

1. viewtopic.php?f=57&t=9158
2. viewtopic.php?f=3&t=9163

[codelast]

Thanks moonman, problem solved.
It's exactly the openssh reason what you mentioned.
I edited the /etc/ssh/sshd_config file and uncomment the following line:
$this->bbcode_second_pass_code('', '#PermitRootLogin yes')
and then I can login with root.
Thanks again.

[vduarte]

I had this exact problem and this fixed it perfectly.

[draecko]

Hi,
Sorry for being super new to arch linux, but I've run into the same problem here, however, I'm running alarm headless. Is there any workaround to fix this without physical access to the machine?

[moonman]

You can't fix it remotely.