Can't set nobreakspace (nbsp) to Shift+Space (level2)

Distribution

Mint 22.1

Package version

6.4.8

Graphics hardware in use

Intel Atom/Celeron/Pentium Processor x5-E8000/J3xxx/N3xxx Integrated Graphics (i915)

Frequency

Always

Bug description

I’m setting up a new notebook with LM 22.1 (Cinnamon/X11), and I need some keyboard settings which worked on my other laptop (currently at LM 21.3) to be the same on this machine.

I use the ibus IMF, have set my keyboard to German (de) "deadtilde" variant, and wish to have the nobreakspace on level2 of the space bar, like on all my other systems. I can set it using the keyboard settings, and it does survive reboots, but it doesn’t work. The keyboard layout preview also doesn’t show it (on my Mint 21.3 laptop it does).

The setxkbmap command produces an error:

$ setxkbmap de pc105 deadtilde grp:win_space_toggle,terminate:ctrl_alt_bksp,keypad:future,nbsp:level2,compose:caps
Error loading new keyboard description
$

(This is my standard keyboard configuration on all my machines.)

The file /etc/default/keyboard contains:

# KEYBOARD CONFIGURATION FILE

# Consult the keyboard(5) manual page.

XKBMODEL="pc105"
XKBLAYOUT="de"
XKBVARIANT="deadtilde"
XKBOPTIONS="grp:win_space_toggle,terminate:ctrl_alt_bksp,keypad:future,nbsp:level2,compose:caps"

BACKSPACE="guess"

gsettings shows this:

$ gsettings list-recursively org.gnome.desktop.input-sources
org.gnome.desktop.input-sources current uint32 0
org.gnome.desktop.input-sources mru-sources @a(ss) []
org.gnome.desktop.input-sources per-window false
org.gnome.desktop.input-sources show-all-sources false
org.gnome.desktop.input-sources sources @a(ss) []
org.gnome.desktop.input-sources xkb-model 'pc105+inet'
org.gnome.desktop.input-sources xkb-options @as []
$ gsettings list-recursively org.cinnamon.desktop.input-sources
org.cinnamon.desktop.input-sources current uint32 0
org.cinnamon.desktop.input-sources show-all-sources false
org.cinnamon.desktop.input-sources sources @a(ss) []
org.cinnamon.desktop.input-sources xkb-options @as []
$ 

ibus info:

$ apt list --installed ibus*
Auflistung… Fertig
ibus-data/noble,noble,now 1.5.29-2 all  [Installiert,automatisch]
ibus-gtk3/noble,now 1.5.29-2 amd64  [Installiert,automatisch]
ibus-gtk4/noble,now 1.5.29-2 amd64  [Installiert,automatisch]
ibus-gtk/noble,now 1.5.29-2 amd64  [Installiert,automatisch]
ibus/noble,now 1.5.29-2 amd64  [installiert]

$ env | grep ibus
GTK_IM_MODULE=ibus
XMODIFIERS=@im=ibus
CLUTTER_IM_MODULE=ibus
QT_IM_MODULE=ibus

Please help. I use this keyboard layout for >13 years now, on all my machines, and have to type the nbsp quite often.

Steps to reproduce

On a German Linux Mint 22.1/Cinnamon system,

• set your keyboard to de, pc105, deadtilde
• set Non-breaking space input to Nicht umbrechbares Leerzeichen in der zweiten Tastaturebene (nobreakspace in level2)
• call up the keyboard layout preview (little keyboard icon at the bottom)
• try typing Shift+Space, it’ll produce a normal blank, not U+00A0

Expected behavior

Respect my keyboard settings.

Additional information

(see above)

Reproduce on Linux Mint 22.1/Cinnamon/X11 with the de pc105 deadtilde layout and the nbsp:level2 option. Check the keyboard layout preview and Shift+Space output, then compare the /etc/default/keyboard, setxkbmap, and gsettings results with the working Mint 21.3 setup. Done means the configured non-breaking space appears in the preview and is emitted by Shift+Space.