Was able to reproduce the issue - funnily enough, the installer will freeze and eventually crash if
German is selected as system language; if I select
British English, it just closes (crashes?) right away.
While browsing through
sudo dmesg | less
in the Manjaro live environment, I found this:
[ 427.279440] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=@,global_oom,task_memcg=/user.slice/user-1000.slice/user@1000.service/session.slice/plasma-plasmashell.service,service,task=calamares,pid=2870,uid=0
Apparently 2048 MiB of RAM aren't enough for the installer. A similar thing happens with the most recent version of EndeavourOS, which is also based on ArchLinux and uses the Calamares installer (Endeavouros_Cassini_Nova-03-2023_R1, using the "online" mode), but in that case it freezes at about ~37% of the installation for me, presumably also because it goes OOM.
Giving both VMs 4096 MiB of RAM each allows the installation to complete; both the Manjaro ISO above (using "Erase Disk" for partitioning) and EndeavourOS Cassini (using online install mode and choosing KDE Plasma as DE, manually configured GPT partition table) will use about ~3.7 GiB during the installation.
Even though either distro should be fine with 2 GiB of RAM when actually in use, it's still surprising to me that the Calamares installer needs more than that. I mean, the average user's hardware will probably have more RAM than that, but still.
Edit: The EndeavourOS installation completes with 4 GiB of RAM, but won't boot afterwards, presumably due to a GRUB issue; I'm not gonna look into that right now, though.