I have upgraded the package
libjson-c to make GIMP work, but it seems like the old version was used by the kernel, which is now unable to boot.
When I choose advanced options in the GRUB menu, both fallback versions (normal + LTS kernel) are not functioning, as I get the same kernel panic message.
The next step I would take, is to boot into a live OS, but I don't know how I would go about reverting the package upgrade.
If the live OS had pacman and I was able to link it with my root partition,
pacman -U /var/cache/pacman/pkg/package-old_version.pkg.tar.xz
would suffice, but I don't know how to achieve that.
In case this is not possible, manually installing the package is also an option, though I don't know in what directory this would be done. Building the package from source and moving it to the correct directory would seem most reasonable in this case. Which directory would this be, though?
I am using Antergos Linux and none of my partitions are encrypted.