I’ve been using Arch Linux for some years, and it’s still my favorite Linux distribution. The feature that distinguished Arch from others is its rolling release which means there’s no such a thing called version in Arch. Using latest packages in Arch is the norm.

However living on the edge means it’s not quite safe. After I installed a bunch of updates including Gnome Shell 3.28, my XPS 15 laptop had trouble to bring up external monitor. It even froze when I plug the HDMI in hot.

I tried to revert some packages like

sudo pacman -U /var/cache/packman/pkg/some-package-1.0.xx.pkg.tar.xz

But it didn’t solve the problem because there were hundreds of packages in last update.

Almost going to panic, I found this instruction to revert all packages to a snapshot in time. And it actually worked wonders for me.

Only surprise is when downgrading packages, I saw errors like

 package-name: /path/to/package-file exists in filesystem

Guess it’s a safe guarding mechanism of pacman but since I know what I was doing so I simply deleted those files. The final command is

sudo pacman -Syyuu

which will bring Arch Linux back to a point of time and the issue has been fixed 🙂