Description: I know this is hilarious, embarrassing and I deserve the Darwin Awards, however it's dangerous for userdel -r to not do sanity check on home address of the user, especially when it's a system user (uid < 1000).

Currently system users for services is automatically created on install through /usr/share/libalpm/hooks/20-systemd-sysusers.hook (shipped with systemd). It invokes systemd-sysusers (systemd utility), which by default sets the home directory of the new user to / if not provided (https://man.archlinux.org/man/sysusers.d.5)

The bundled /usr/lib/sysusers.d/libvirt.conf with libvirt (generated in PKGBUILD) does not specify the home path for this user. Therefore its home in /etc/passwd would be /

When I executed userdel -r libvirt-qemu, the commands doesn't exit for a few seconds. Then it exit with errors complaining resource is busy for /. Then I realise that all the files in my /home/user is gone except for ~/Desktop. The rest of file system seems intact, I don't understand why (I use a partition for / and another for /home).

Additional info:
* package version(s)
shadow 4.13-2
libvirt 1:9.4.0-1
* config and/or log files etc.
* link to upstream bug report, if any
This is hilarious. I'm not sure if it should count as an upstream bug.

Steps to reproduce:
1. pacman -S libvirt
2. ### DONT DO THIS ### userdel -r libvirt-qemu