[arch-general] Cannot recover pacman upgrade fails problem

[Emil Lundberg]

Good to hear you got it working! As for some of your earlier questions...

>      Thank you for giving suggestions, I have tried the one you suggest, and here is the result:
> [...]
> #ls /mnt/sda3
> /boot,dev/,etc/,home/,opt/,lost+found/,proc/,root/,run/,srv/,usr/,var/,sys/.
> [...]
> #mount /dev/sda3 /mnt
> #mount /dev/sda2 /mnt/boot
> #arch-chroot /mnt
> failed to run command /bin/sh, no such file or directory
>
> When  I try using /dev/mapper/arch_root-image as root partition, the arch-chroot works, that's why I am using that. Is there any problem in my command?

The problem is that the shell executable /bin/sh doesn't exist in the
sda3 filesystem (notice that /bin is missing from the ls output).
/dev/mapper/arch_root-image is the liveUSB filesystem (I'll assume
you're using a liveUSB and not liveCD) which has the /bin/sh
executable, so that's why chrooting works when you mount that as /mnt.
However, mounting arch_root-image as /mnt won't help you recover your
system since any changes to the filesystem after chrooting would be
done to the liveUSB filesystem and not the one on your hard drive.

> I use this system for almost one year, and don't update the system. I have tried mount /dev/sda3 as the root directory. And I try one thing before chroot:
> #mkdir /mnt/bin
> #cp /bin/* /mnt/bin
> #arch-chroot /mnt
>
> Now I can go to the chroot jail. And surprised to me, I run the following command, and I don't see any fails:
> #mv /bin/* /usr/bin/
> #rmdir /bin
> #pacman -Syu mkinitcpio systemd linux

The above is the reason why this worked.