Hi! Update went fine:
- updated from TTY without any other logged session.
- haven't updated the 3 systemd packages mentioned by @philm at top of the thread. I'll wait for the next release of systemd.
Some suggestions for those stuck at a black screen after successfully booting grub:
Try to downgrade libsystemd, systemd and systemd-sysvcompat packages:
- login through TTY as root (or use sudo if you don't)
ls /var/cache/pacman/pkg | grep systemd
- note the filename of the previous version of the 3 packages mentioned above. On my system they are libsystemd-231-1-i686.pkg.tar.xz, systemd-231-1-i686.pkg.tar.xz and systemd-sysvcompat-231-1-i686.pkg.tar.xz (this might differ in your system).
# pacman -U /var/cache/pacman/pkg/libsystemd-231-1-i686.pkg.tar.xz /var/cache/pacman/pkg/systemd-231-1-i686.pkg.tar.xz /var/cache/pacman/pkg/systemd-sysvcompat-231-1-i686.pkg.tar.xz
# reboot now
If this doesn't work and you use proprietary drivers (especially nvidea ones, because they seem more problematic), try to do the same with those or switch to free drivers to see if the problem goes away.
If this still doesn't work try an older kernel (linux41, for example).
If I'm completely wrong and peeing off the pot, sorry! Just trying to help.
I use krusader-git in KDE and i3 and it doesn't seem to depend on qt4. I had to install some KDE packages on i3 for it work properly, including plasma-workspace and kuiserver5 (it works fine without it, but things like thumbnailing and networking need extra packages). However, I don't start KDE as I login (only kuiserver5), so I don't get the memory footprint. Krusader only uses kio slaves as it needs and then turns them off. It works much better that krusader 2.4.0.