systemd-vconsole-setup.service may fail if the user specifies a missing keymap,
see [1,2,3], or font. This is unfortunate, but the system should not refuse
boot. It is better to continue, possible without the desired font or keymap.
All other systemd services that depend on systemd-vconsole-setup.service do so
without a hard Requires=.
(In particular, systemd-vconsole-setup internally will try to do as much setup
as possible, and will load the font even if it cannot load the keymap and vice
versa.)
[1] https://fedoraproject.org/wiki/Common_F34_bugs#kbd-legacy-media
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1955162
[3] https://bugzilla.redhat.com/show_bug.cgi?id=1955793
This is what happened before this patch (edited for brevity):
dracut-cmdline-ask.service in modules.d/98dracut-systemd, which invokes
dracut-cmdline-ask.sh. This script and systemd-vconsole-setup are
started in parallel for the same console (tty1).
Then dracut-cmdline-ask quits immediately without doing anything (unless
rd.cmdline=ask is given). As this is a bash script and it gets tty as
stdin as specified in its *.service, this triggers the hangup of tty1 at
its exit.
Meanwhile systemd-vconsole-setup continues and tries some ioctls after
that, but they fail because of the hung up tty1.
The usual culprit for starting systemd-vconsole-setup early on is
plymouth-start.service, even if plymouth.enable=0 is set.
A popular (and annoying) symptom of this as reported by users was
the inability use their configured keyboard layout in plymouth when
unlocking their crypted block devices.
Reference: boo#1055834
Basic systemd functionality is in 00systemd now.
Switching root and the initrd.target is in 00systemd-initrd.
Dracut additions to the systemd initrd are in 98dracut-systemd.
Zbigniew Jędrzejewski-Szmek