the reason why virtualbox can not be installed with pacman, is because it has non-free software components, and so is on the blacklist - the FSDG prevents distros from helping users to install non-free software; so strictly speaking, this question should not be answered on this forum

i would suggest using QEMU instead (or one of it's GUI front-ends, virt-manager, gnome-boxes, x2go, etc.)

WRT specifically to the error message, that is not reporting an error - it is failing because there is no such package in the repos named: 'lib32-libstdc++5' - as general advice, you should avoid installing any software other than what is in your distro's repos - if you are going to install third-party software, you will need to become familiar with acquiring/compiling/installing PKGBUILDs - you could probably find a PKGBUILD for both virtualbox and that missing dependency; but again, it is not permitted to help you do so on parabola's channels

Too bad.

I tried to run Qemu with openRC but it was a headache.

Are there any proper docs for Qemu with openrc or any other virtualization software?

i use QEMU on a parabola openrc system every day - there is nothing specific to note regarding openrc - QEMU works exactly the same with any init-system (that is true for nearly all programs) - if you are having problems using QEMU, that is something we could discuss

if you need a generic command, this one is suitable for most uses (just change /path/to/vm.img):

$ qemu-system-x86_64 -enable-kvm -cpu host -smp cores=2,threads=2,sockets=2 -m 2G -vga std -device AC97 -drive file=/path/to/vm.img,format=raw,cache=writeback

if you do not have a VM image to boot, you would need to create an empty vm.img (a virtual hard disk), with this command:

$ qemu-img create vm.img 20G

and boot a liveISO, by adding the following options to the qemu command (changing /path/to/some.iso):

 -cdrom /path/to/some.iso -boot order=d

QEMU is not the not very user-friendly on the command line; but the GUI front-ends that i mentioned give the same familiar user-friendly experience as virtualbox - probably, you would have no trouble using one of those

Oops, tried installing Qemu according to another site before knowing that there's a parabola doc for Qemu

But I still get these errors (see file) form section 2 of the parabola doc

again, those errors are because you are trying to install packages which do not exist - there are no packages named 'qemu-launcher' or 'qtemu' - the name of the qemu package is 'qemu'

# pacman -S qemu

# pacman -S gnome-boxes

I still can't run the GUI.

I tried to be root and run the GUI shortcut file placed on desktop and the errors are in the file

I still can't run the GUI.

youd need to be more specific - which program? - i just
installed virt-manager and gnome-boxes; and they both work as
expected

The "Virtual Machine Manager" GUI of qeumu

i assume that is virt-manager - generally, if some program fails
to start using the desktop shortcut, open a terminal and try
running the program by it's command (in this case:
virt-manager), and see if there are any error messages

Turns out, libvirt was missing from my system when I was cleaning systemd related files last time (sadly, MATE still uses some systemd files)

Tried QEMU again and now it semi works.

Now, I get the error in file whenever I try to run a new VM and says the same error when I used the systemd route

many openrc service files are in separate packages named ending with *-openrc (in this case: 'libvirt-openrc') - if such a package exists, you would generally need to install it - however, in this case, there is a bug preventing it from being installed

i did not notice the bug yesterday, because i did not try to create a VM - there is an open bug report about it (#1658), which was apparently forgotten

gnome-boxes seems to be working properly - i would suggest using gnome-boxes until #1658 is fixed

Followed your instructions but ended up with these errors for gnome-boxes

you should not run GUI programs as root, or from a VT shell without a desktop - run gnome-boxes as a normal unprivileged user, from a running desktop session

Found the Boxes hidden in the Programming menu for some reason.

But now I used the ISO file I wanted but instead of going on, it kept stuck on the "Review" page as a blank

sry, i am not familiar with those GUI VM launchers -
gnome-boxes worked for me with a parabola ISO - maybe
find some gnome-boxes users to ask for help

the qemu command lines above will almost certainly work for
anyone