Arch Linux

bradrn

Member

Registered: 2022-05-07

Posts: 18

AltGr does not work with IBus/m17n

(Disclaimer: not sure if this post is entirely on topic in this subforum; please let me know if I should move it somewhere else!)

My problem is quite simply as in the subject: the AltGr (well, Right Alt) key does not work when using an m17n input method in IBus, in that it seems to have no effect. Curiously enough, the problem occurs only with IBus and m17n: keyboard layouts defined outside m17n work fine, while using m17n with another input method doesn't seem to work well at all. Furthermore, I have tested multiple different m17n layouts within IBus (including my own custom one), and they all work very well otherwise, the sole problem being the AltGr key.

Here's what xev outputs for Right Alt:

KeyPress event, serial 34, synthetic NO, window 0x5600001,
    root 0x7c1, subw 0x0, time 866413, (679,796), root:(4522,1039),
    state 0x0, keycode 108 (keysym 0xffea, Alt_R), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5600001,
    root 0x7c1, subw 0x0, time 866493, (679,796), root:(4522,1039),
    state 0x8, keycode 108 (keysym 0xffea, Alt_R), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

And xmodmap:

$ xmodmap
xmodmap:  up to 4 keys per modifier, (keycodes in parentheses):

shift       Shift_L (0x32),  Shift_R (0x3e)
lock        Caps_Lock (0x42)
control     Control_L (0x25),  Control_R (0x69)
mod1        Alt_L (0x40),  Alt_R (0x6c),  Alt_L (0xcc),  Meta_L (0xcd)
mod2        Num_Lock (0x4d)
mod3        ISO_Level5_Shift (0xcb)
mod4        Super_L (0x85),  Super_R (0x86),  Super_L (0xce),  Hyper_L (0xcf)
mod5        ISO_Level3_Shift (0x5c)

$ xmodmap -pk | grep '108'
    108    	0xffea (Alt_R)	0xffe8 (Meta_R)	0xfe03 (ISO_Level3_Shift)

Running ‘xmodmap -e "keycode 108 = ISO_Level3_Shift"‘ changes the xmodmap output, but otherwise seems to have no observable effect whatsoever.

Annoyingly, this problem seems to reoccur across distros and desktop environments: I've had precisely the same issue on Arch Linux with Xfce+XMonad, EndeavourOS with the same environment, and NixOS with XMonad. On the other hand, I did once manage to get it working on Ubuntu — using Unity at the time, as I recall — and wrote up the procedure I used to do so, but that was in a virtual machine hosted on Windows, which may have affected matters. Does anyone have any ideas as to what might be the problem here, and how I might fix it? I've been struggling with this for about two months now, and have run out of ideas…