switching layout in tty

[Roman Riabenko via <help-guix@gnu.org>]

Hello

I am trying to navigate my home directory on a tty console, for example
after pressing Ctrl+Alt+F3, on a Guix System with GNOME desktop. This
requires utilising Latin and Cyrillic characters.

I used the graphical install for the system installation and initially
left the default Alt+Shift to switch the layout. This worked fine
during the installation.

However, now I have to press it multiple times to switch from English
to another language. Finally, after switching, I cannot switch back to
English. Instead, when pressing the shortcut, the console occasionally
gets into a state where it does not show any input until the layout is
switched back to non-Latin. Enter key and other shortcuts stop working
entirely.

I tried to set a different shortcut, such as both Shifts pressed
simultaneously. The option for this is grp:shifts_toggle per man
xkeyboard-config. This stops Alt+Shift from working. But the new
combination also does nothing.

For comparison, under the graphical interface, the Alt+Shift is not
managed by the GNOME shell considering that it is not listed in the
shortcuts and even conflicts with one of the default GNOME shortcuts.
So, I guess that it should be set the same way. However, the shortcut's
behaviour in the desktop environment is different. When pressed, it
cycles through two instances of Latin and one Cyrillic. I couldn't
identify the difference between the Latin instances. I only have the
English (US) layout configured in the guix system configuration and the
GNOME Settings.

Changing the shortcut to both Shifts in guix system configuration did
not affect the shortcut in GNOME at all.

How do I change or disable this Alt+Shift shortcut properly? How do I
configure a shortcut to switch the layouts on the tty?

$ grep locale /etc/config.scm -B 1 -A 3
(operating-system
  (locale "uk_UA.utf8")
  (timezone "Europe/Kyiv")
  (keyboard-layout (keyboard-layout "us,ua"
                                    #:options '("grp:shifts_toggle")))
$ localectl status
   System Locale: n/a
       VC Keymap: n/a
      X11 Layout: us,ua
     X11 Options: grp:shifts_toggle
$ guix describe
Generation 13	04 січ 2025 20:47:51	(current)
  guix b8858d8
    repository URL: https://git.savannah.gnu.org/git/guix.git
    вітка: master
    коміт: b8858d8b1344525d0d7ac78d8fb9dc1a577b85d3

Roman