bug(linux): Backspace Issues for SIL IPA Keyboard with Wayland

[jonwalls-oxling]

Describe the bug

When using the SIL IPA keyboard, backspace issues of various kinds appear (may or may not be related). In particular:

• Composing a character by typing n + > yields nŋ, when it should delete the original character, leaving only ŋ
• Backspacing in normal typing to delete mistakes, etc., takes mashing the backspace key until it finally registers and backspaces correctly.

Reproduce the bug

For the first issue:

1. Select the SIL IPA keyboard
2. Attempt character combination
3. Observe that the original character remains

For the second:

1. Select the SIL IPA keyboard
2. Attempt to backspace
3. Observe that most backspace presses are ignored

Expected behavior

Backspacing generally should be predictable and function both on keypress and as required for character composition.

Related issues

No response

Keyman apps

• Keyman for Android
• Keyman for iPhone and iPad
• Keyman for Linux
• Keyman for macOS
• Keyman for Windows
• Keyman Developer
• KeymanWeb
• Other - give details at bottom of form

Keyman version

18.0.236 to 19.0.227

Operating system

Arch Linux 7.0.3-arch1-2, KDE Plasma 6.6.4, Wayland session

Device

No response

Target application

Firefox, Chromium, LibreOffice Writer, etc. (appears global)

Browser

No response

Keyboard name

IPA (SIL)

Keyboard version

2.0.2

Language name

No response

Additional context

I have tried this with the stable Keyman 18 version as well as the latest Keyman alpha version, they both show the problem. It occurs throughout my whole system, not just on a specific application.

[ermshiperete]

@jonwalls-oxling What ibus version do you have installed?

The latest Keyman alpha version comes with a km-diag-report command line tool. Please run that and post the output.

[jonwalls-oxling]

@ermshiperete Good question, apologies I meant to include that earlier!

I have the following output from km-diag-report:

============================================================
Keyman for Linux Diagnostic Report (2026-05-07)
============================================================

--- Keyman Version ---
  Version: 19.0.227-alpha-local
  Tier: alpha
  Package version: (local)

--- IBus ---
  IBus version: 1.5.33 (Running)
  Preload engines: xlc:/home/glottophilos/.local/share/keyman/lycian/lycian.kmx, xld:/home/glottophilos/.local/share/keyman/lydian/lydian.kmx, arc:/home/glottophilos/.local/share/keyman/imperial_aramaic/imperial_aramaic.kmx, xkb:us:altgr-intl:eng, und-Latn:/home/glottophilos/.local/share/keyman/sil_ipa/sil_ipa.kmx

--- Operating System ---
  OS: Arch Linux
  Kernel: 7.0.3-arch1-2
  Architecture: x86_64

--- Display Server ---
  Session type: wayland
  Wayland display: wayland-0
  X11 display: :0

--- Desktop Environment ---
  Current desktop: KDE
  Session desktop: KDE
  Desktop session: /usr/share/wayland-sessions/plasma.desktop

--- Input Method Configuration ---
  GTK_IM_MODULE: ibus
  QT_IM_MODULE: ibus
  XMODIFIERS: @im=ibus

--- Installed Keyman Keyboards ---
  User keyboards:
    - Lycian (id: lycian, version: 1.0)
    - IPA (SIL) (id: sil_ipa, version: 2.0.2)
    - Lydian (id: lydian, version: 1.0)
    - Imperial Aramaic (id: imperial_aramaic, version: 1.0.1)

--- Web Browsers ---
  Pacman packages (Arch):
    - firefox: 150.0.1-1
    - chromium: 148.0.7778.96-1
  Default browser:
    /usr/share/applications/firefox.desktop (/usr/lib/firefox/firefox)

============================================================
End of Diagnostic Report
============================================================

Edit: updating output to show from very slightly different system instead, same issue on both though, differences are irrelevant but just wanted to use the output from the system that does have the input method configs all set so it's clear that those aren't the issue

[ermshiperete]

@jonwalls-oxling Thanks! It's likely that this has been fixed with ibus 1.5.34 - at least it contains several commits touching the Wayland client. And in my testing with Ubuntu 26.04 with Wayland and gnome-shell and ibus 1.5.34 things worked better than in previous versions - although there are still some problems in Firefox and Chromium.

[jonwalls-oxling]

@ermshiperete It seems like it is helping! I switched to 1.5.34 and it looks like at least in Firefox and Chromium, the issues are gone. LibreOffice is still behaving a bit funny, but it's not as bad as it was. Can't begin to guess what the difference is there, maybe you have a better sense?

[ermshiperete]

@jonwalls-oxling Great that it's working better with the current ibus version!

LibreOffice is still behaving a bit funny, but it's not as bad as it was.

What's not working right? I just did a quick test with Ubuntu 26.04, KDE and LibreOffice 26.2.2.2 and I didn't notice problems with SIL IPA or backspace.

Out of curiosity: I see that "Preload engines" in the diag report show "xlc:..." and "xld:...". What other software do you have installed that can load .kmx keyboards?