I hope this is the right place to post this!?
I ran into problems with grub and thought the easiest way was to reboot from install-image and chroot.
To be sure I was using chroot right I read arch-wiki about chroot. In chroot I got stuck though! Could not update grub config or reinstall grub to mbr (I have a the old type of machine!) The reason was “could not find device for / . Is /dev mounted”. Searched for this problem on arch-wiki but couldn’t find anything that helped me.
Then I thought that maybe I could update grub through the installer? I tried to do that by choosing to install as little as possible. Did not work well . The system started but hang and had to “hard-shutdown”!
The only solution I could come up with after this was to reinstall. (A bit dissappointing because I had made a lot of personal configurations!)
(I apologize for this boring rant!)
Live-image could have tools for fixing troubles with boot and a helper for chrooting into the installed system.