Immediate segmetation fault with the official version of Anki [Linux]

Anki Help
1

Downloading and installing the main x86-64 version of Anki listed on the https://apps.ankiweb.net site causes an immediate segmentation fault. The suggestions from Segfault on startup - #11 by danko and Segfault when trying to start Anki on Linux - #8 by jetri do not fix the issue for me. I’m running on SteamOS:

Operating System: SteamOS 3.8.11 Build: 20260620.1
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.16.12-valve24-2.1-neptune-616-gc748040e4712 (64-bit)
Graphics Platform: Wayland
Partition: B
Processors: 8 × AMD Custom APU 0405
Memory: 16 GiB of RAM (14.5 GiB usable)
Graphics Processor: AMD Custom GPU 0405
Manufacturer: Valve
Product Name: Jupiter
System Version: 1

The debug output of Anki is:

Starting Anki 26.05... 
 File "<frozen runpy>", line 198, in \_run_module_as_main 
 File "<frozen runpy>", line 88, in \_run_code 
 File "/home/runner/work/anki/anki/out/installer/build/anki/linux/zip/anki/app/anki/\__main_\_.py", line 21, in <module> 
 File "/home/runner/work/anki/anki/out/installer/build/anki/linux/zip/anki/app/anki/app.py", line 8, in main 
 File "/home/runner/work/anki/anki/out/installer/build/anki/linux/zip/anki/app_packages/aqt/\__init_\_.py", line 585, in run 
 File "/home/runner/work/anki/anki/out/installer/build/anki/linux/zip/anki/app_packages/aqt/\__init_\_.py", line 657, in \_run 
 File "/home/runner/work/anki/anki/out/installer/build/anki/linux/zip/anki/app_packages/aqt/profiles.py", line 144, in setupMeta 
 File "/home/runner/work/anki/anki/out/installer/build/anki/linux/zip/anki/app_packages/aqt/profiles.py", line 435, in \_loadMeta 
resetting corrupt \_global 
Qt info: OpenType support missing for "Noto Sans CJK JP Light", script 15  
Qt info: OpenType support missing for "Noto Sans CJK JP", script 15  
Segmentation fault         (core dumped) anki

The core dump it generates is:

           PID: 428862 (anki)
           UID: 1000 (deck)
           GID: 1000 (deck)
        Signal: 11 (SEGV)
     Timestamp: Thu 2026-07-02 14:07:46 IST (4min 50s ago)
  Command Line: anki QTWEBENGINE_CHROMIUM_FLAGS=--disable-gpu
    Executable: /usr/local/share/anki/anki
 Control Group: /user.slice/user-1000.slice/user@1000.service/app.slice/app-org.kde.konsole@35113cec8efa4dcca4fdde01afc5aee3.service
          Unit: user@1000.service
     User Unit: app-org.kde.konsole@35113cec8efa4dcca4fdde01afc5aee3.service
         Slice: user-1000.slice
     Owner UID: 1000 (deck)
       Boot ID: 91ed46b9d9314db283c8004b0c264ec0
    Machine ID: f63fef67273545bfa8ac54439eb405b3
      Hostname: steamdeck
       Storage: /var/lib/systemd/coredump/core.anki.1000.91ed46b9d9314db283c8004b0c264ec0.428862.1782997666000000.zst (inaccessible)
       Message: Process 428862 (anki) of user 1000 dumped core.
                
                Module _message.abi3.so without build-id.
                Module libpython3.13.so.1.0 without build-id.
                Stack trace of thread 428862:
                #0  0x00007f49121e2ba4 _ZNK7QObject6threadEv (libQt6Core.so.6 + 0x1e2ba4)
                #1  0x00007f49121ee912 _ZN7QObjectC1ER14QObjectPrivatePS_ (libQt6Core.so.6 + 0x1ee912)
                #2  0x00007f48fed22ef3 _ZN5fcitx24FcitxQtInputContextProxyC1EPNS_14FcitxQtWatcherEP7QObject (libFcitx5Qt6DBusAddons.so.1 + 0x46ef3)
                #3  0x00007f4914f0915c _ZN5fcitx26QFcitxPlatformInputContext12createICDataEP7QWindow (libfcitx5platforminputcontextplugin.so + 0x1b15c)
                #4  0x00007f4914f0cdeb _ZN5fcitx26QFcitxPlatformInputContext14setFocusObjectEP7QObject (libfcitx5platforminputcontextplugin.so + 0x1edeb)
                #5  0x00007f490e9e95db _ZN22QGuiApplicationPrivate20_q_updateFocusObjectEP7QObject (libQt6Gui.so.6 + 0x1e95db)
                #6  0x00007f49121f1cc0 n/a (libQt6Core.so.6 + 0x1f1cc0)
                #7  0x00007f490ea57cd6 _ZN7QWindow18focusObjectChangedEP7QObject (libQt6Gui.so.6 + 0x257cd6)
                #8  0x00007f490d7f0e9b _ZN7QWidget8setFocusEN2Qt11FocusReasonE (libQt6Widgets.so.6 + 0x1f0e9b)
                #9  0x00007f490d79a53c _ZN19QApplicationPrivate15setActiveWindowEP7QWidget (libQt6Widgets.so.6 + 0x19a53c)
                #10 0x00007f490d79a79d _ZN19QApplicationPrivate24notifyActiveWindowChangeEP7QWindow (libQt6Widgets.so.6 + 0x19a79d)
                #11 0x00007f490e9fc108 _ZN22QGuiApplicationPrivate23processFocusWindowEventEPN29QWindowSystemInterfacePrivate16FocusWindowEventE (libQt6Gui.so.6 + 0x1fc108)
                #12 0x00007f490ea6414c _ZN22QWindowSystemInterface22sendWindowSystemEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Gui.so.6 + 0x26414c)
                #13 0x00007f490ef96774 n/a (libQt6Gui.so.6 + 0x796774)
                #14 0x00007f491170887d n/a (libglib-2.0.so.0 + 0x5e87d)
                #15 0x00007f4911709cd7 n/a (libglib-2.0.so.0 + 0x5fcd7)
                #16 0x00007f4911709ee5 g_main_context_iteration (libglib-2.0.so.0 + 0x5fee5)
                #17 0x00007f49124981de _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x4981de)
                #18 0x00007f4912196abb _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x196abb)
                #19 0x00007f490da17acd _ZN7QDialog4execEv (libQt6Widgets.so.6 + 0x417acd)
                #20 0x00007f490e08c6d8 meth_QDialog_exec (QtWidgets.abi3.so + 0x28c6d8)
                #21 0x00007f4916344cc6 cfunction_call (libpython3.13.so.1.0 + 0x344cc6)
                #22 0x00007f49163b4080 _PyEval_EvalFrameDefault (libpython3.13.so.1.0 + 0x3b4080)
                #23 0x00007f491656efa6 PyEval_EvalCode (libpython3.13.so.1.0 + 0x56efa6)
                #24 0x00007f491656cb39 builtin_exec (libpython3.13.so.1.0 + 0x56cb39)
                #25 0x00007f491634458b cfunction_vectorcall_FASTCALL_KEYWORDS.llvm.574017895900248814 (libpython3.13.so.1.0 + 0x34458b)
                #26 0x00007f49163b3cd0 _PyEval_EvalFrameDefault (libpython3.13.so.1.0 + 0x3b3cd0)
                #27 0x00005564fdcc2ca4 n/a (/usr/local/share/anki/anki + 0x2ca4)
                #28 0x00007f4915e376b5 n/a (libc.so.6 + 0x276b5)
                #29 0x00007f4915e37769 __libc_start_main (libc.so.6 + 0x27769)
                #30 0x00005564fdcc2e85 n/a (/usr/local/share/anki/anki + 0x2e85)
                
                Stack trace of thread 428929:
                #0  0x00007f4915eade22 n/a (libc.so.6 + 0x9de22)
                #1  0x00007f4915ea1fda n/a (libc.so.6 + 0x91fda)
                #2  0x00007f4915ea2024 n/a (libc.so.6 + 0x92024)
                #3  0x00007f4915f1c0de __poll (libc.so.6 + 0x10c0de)
                #4  0x00007f48fe9677f0 n/a (libQt6WaylandClient.so.6 + 0x987f0)
                #5  0x00007f491235a76e n/a (libQt6Core.so.6 + 0x35a76e)
                #6  0x00007f4915ea57eb n/a (libc.so.6 + 0x957eb)
                #7  0x00007f4915f2920c n/a (libc.so.6 + 0x11920c)
                
                Stack trace of thread 428925:
                #0  0x00007f4915eade22 n/a (libc.so.6 + 0x9de22)
                #1  0x00007f4915ea1fda n/a (libc.so.6 + 0x91fda)
                #2  0x00007f4915ea2024 n/a (libc.so.6 + 0x92024)
                #3  0x00007f4915f1c626 ppoll (libc.so.6 + 0x10c626)
                #4  0x00007f4911709e04 n/a (libglib-2.0.so.0 + 0x5fe04)
                #5  0x00007f4911709ee5 g_main_context_iteration (libglib-2.0.so.0 + 0x5fee5)
                #6  0x00007f49124981de _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x4981de)
                #7  0x00007f4912196abb _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x196abb)
                #8  0x00007f49122a7113 _ZN7QThread4execEv (libQt6Core.so.6 + 0x2a7113)
                #9  0x00007f4911a807ce n/a (libQt6DBus.so.6 + 0x407ce)
                #10 0x00007f491235a76e n/a (libQt6Core.so.6 + 0x35a76e)
                #11 0x00007f4915ea57eb n/a (libc.so.6 + 0x957eb)
                #12 0x00007f4915f2920c n/a (libc.so.6 + 0x11920c)
                
                Stack trace of thread 428930:
                #0  0x00007f4915eade22 n/a (libc.so.6 + 0x9de22)
                #1  0x00007f4915ea1fda n/a (libc.so.6 + 0x91fda)
                #2  0x00007f4915ea2024 n/a (libc.so.6 + 0x92024)
                #3  0x00007f4915f1c0de __poll (libc.so.6 + 0x10c0de)
                #4  0x00007f48fe9677f0 n/a (libQt6WaylandClient.so.6 + 0x987f0)
                #5  0x00007f491235a76e n/a (libQt6Core.so.6 + 0x35a76e)
                #6  0x00007f4915ea57eb n/a (libc.so.6 + 0x957eb)
                #7  0x00007f4915f2920c n/a (libc.so.6 + 0x11920c)
                ELF object binary architecture: AMD x86-64

This happens every time I try to start Anki.

2

Do you have fcitx4 installed? Can you try this workaround?

3

I have fcitx5 installed and this actually did fix the issue for me, thanks.

4

I hit the same segfault (Ubuntu 24.04, X11, fcitx5) and asked Claude “Fable” to debug it. Its findings confirm what abdo-san suspected, and explain why the bundled plugin crashes:

With QT_DEBUG_PLUGINS=1, every bundled Qt plugin reports "version": 396032 (Qt 6.11.0), except libfcitx5platforminputcontextplugin.so, which reports "version": 393728 (Qt 6.2.0). So the 26.05 tarball ships a fcitx5 input context plugin built against Qt 6.2 inside a Qt 6.11 application, and the ABI mismatch segfaults as soon as a window receives focus (right after “Starting main loop…”).

gdb backtrace (top frames):

#0  QObject::thread() const                              (libQt6Core.so.6)
#1  QObject::QObject(QObjectPrivate&, QObject*)
#2  fcitx::FcitxQtInputContextProxy::FcitxQtInputContextProxy(...)  (libFcitx5Qt6DBusAddons.so.1)
#3  fcitx::QFcitxPlatformInputContext::createICData(QWindow*)
#4  fcitx::QFcitxPlatformInputContext::setFocusObject(QObject*)

It only triggers with QT_IM_MODULE=fcitx (typical for CJK input on Linux), which is why many setups don’t reproduce it.

For those who need CJK input inside Anki, there’s a workaround that avoids the crash and keeps the input method working, without deleting files from the installation:

QT_IM_MODULE=ibus IBUS_USE_PORTAL=1 anki

This works because fcitx5 exposes an IBus-compatible interface on DBus (org.freedesktop.portal.IBus), and the bundled ibus plugin is correctly built against Qt 6.11. So Qt talks to fcitx5 through its IBus emulation, bypassing the broken fcitx plugin. Confirmed working with Japanese input on my machine.

(Note: QT_IM_MODULE=xim also avoids the crash, but on Qt 6 that just maps to the compose plugin — real XIM support was removed — so CJK input doesn’t work with it.)

Not graphics-related, for the record: it crashes identically with NVIDIA driver 535 and 595, with --disable-gpu, and even with QT_QPA_PLATFORM=offscreen.

5

Will be hopefully fixed in the next beta: