About 1 boot in 10 of an installed system stops on a black screen at
"Starting Switch Root" until a key is pressed. systemd 257 and later
asks the console for its size with ANSI escape sequences when PID 1
starts and waits for the reply; with Plymouth holding the VT the reply
sometimes never comes.
Measured in QEMU on repeated boots of one install: 3 hangs in 30 and 1
in 40 on the prebuilt UKI, 7 in 40 on the stock initramfs, every one of
them ended by pressing Enter; none in 40 with a serial console, none in
40 with plymouth.enable=0, and none in 80 with
systemd.tty.term.console=dumb, which makes systemd skip the query.
systemd fixed two variants of this in v261; Arch's 261.2 still shows it.
The parameter goes where the last Plymouth boot fix went (3f725531,
initramfs_async=0): into the packaged omarchy-defaults.conf for fresh
installs, and a migration rebuilds the boot image on existing systems,
once per machine, only where the booted command line lacks it. Nothing
visible changes under "quiet splash".
Refs #2931
Keep the migrations themselves for late-updaters. Drop the tests that only
exercised frozen file rewrites from 4.0.0, and keep live invariants,
privileged repairs, and the migrator.
Emir Beganovic