Arch Linux configuration management
It turns out that tracking tweaks to the system, Arch Linux in my case, is a common concern. And it has already been solved by aconfmgr. This is a shell script, which calculates what has changed in the system: installed or removed packages; added, removed or changed files.
I believe this is a good opportunity to ease management of my laptop. So there I have it: arch-config. It will naturally complement my earlier attempt to manage dotfiles.