Un-busting GRUB with arch-chroot

properly this time

1. Boot from archiso CD/DVD/USB

2. Prepare dir structire - in my case, it was:

    mount /dev/nvme0n1p6 -o subvol=@ /mnt
    mount /dev/nvme0n1p1 /mnt/boot/efi
   

   Hint: to find out proper patition names, you can use lsblk and lsblk -f commands.

3. chroot to it

    arch-chroot /mnt
   

4. Fix your problem!

    grub-install
   

Also see "10 use the power of arch-chroot when your computer crashes".

Remember the -o subvol=@ thingy to mount the proper subvol! Otherwise, you'll have to mount --bind /mnt/@ /mnt/@ before the second mount command (otherwise grub-install won't find root filesystem in /dev), and use proper path (/mnt/@ instead of /mnt) in the following commands