Flatpak crashes with 11/SEGV, possible GTK issue.

[PadenZach]

Describe the bug

Alpaca frequently crashes with segv.

Example:

1. Start new chat
2. Ask question
3. Streaming response begins, I see output.
4. Before message completes, everything crashes
5. Reopening the chat shows that I've created it and asked a question, but no response is saved/recorded even if I export the chat.

I've been using openrouter and sonnet 4.5 here, some others give me similar issues. I also have a 5k token limit configured.

Expected behavior

No crashing :)

Screenshots

If applicable, add screenshots to help explain your problem.

Debugging information

$ flatpak run com.jeffser.Alpaca 

(process:2): Gtk-WARNING **: 13:13:46.078: Unknown key gtk-modules in /home/zpaden/.var/app/com.jeffser.Alpaca/config/gtk-4.0/settings.ini
INFO	[main.py | main] Alpaca version: 8.3.1

(python3:2): Adwaita-WARNING **: 13:13:48.792: Using GtkSettings:gtk-application-prefer-dark-theme with libadwaita is unsupported. Please use AdwStyleManager:color-scheme instead.

(python3:2): Gtk-WARNING **: 13:13:49.613: Trying to snapshot GtkStack 0x55712e0dc4b0 without a current allocation
INFO	[_client.py | _send_single_request] HTTP Request: POST https://openrouter.ai/api/v1/chat/completions "HTTP/1.1 200 OK"

(python3:2): Gtk-CRITICAL **: 13:14:05.667: gtk_text_attributes_ref: assertion 'values != NULL' failed

(python3:2): Pango-CRITICAL **: 13:14:05.668: pango_layout_new: assertion 'context != NULL' failed

journalctl | rg -i alpaca

Nov 09 13:00:58 bazzite systemd[1912]: Started app-flatpak-com.jeffser.Alpaca-1617106792.scope.
Nov 09 13:00:58 bazzite alpaca[37660]: Unknown key gtk-modules in /home/zpaden/.var/app/com.jeffser.Alpaca/config/gtk-4.0/settings.ini
Nov 09 13:01:00 bazzite flatpak[37660]: INFO        [main.py | main] Alpaca version: 8.3.1
Nov 09 13:01:50 bazzite audit[37660]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=37660 comm="alpaca" exe="/usr/bin/python3.13" sig=11 res=1
Nov 09 13:01:50 bazzite kernel: alpaca[37660]: segfault at 4 ip 00007f21cd4b6d74 sp 00007ffd21aa0270 error 4 in libgtk-4.so.1.2000.2[2b6d74,7f21cd2e8000+519000] likely on CPU 1 (core 1, socket 0)
Nov 09 13:01:50 bazzite systemd-coredump[37889]: Process 37660 (alpaca) of user 1000 terminated abnormally with signal 11/SEGV, processing...
Nov 09 13:01:53 bazzite systemd-coredump[37890]: Process 37660 (alpaca) of user 1000 dumped core.
Nov 09 13:01:53 bazzite systemd[1912]: app-com.jeffser.Alpaca@0722376399d24aaabe01da1e37e8466f.service: Main process exited, code=exited, status=139/n/a
Nov 09 13:01:53 bazzite systemd[1912]: app-com.jeffser.Alpaca@0722376399d24aaabe01da1e37e8466f.service: Failed with result 'exit-code'.
Nov 09 13:01:53 bazzite systemd[1912]: app-flatpak-com.jeffser.Alpaca-1617106792.scope: Consumed 14.539s CPU time, 453.7M memory peak.

[taimila]

Yep, same exact thing happens to me. During the model is streaming it's answer Alpaca crashes and answer is lost.

[kimocoder]

In ollama_instances.py, the stop() method has potential race conditions when stopping the Ollama process.
There is also multiple threads accessing self.process without proper locking could cause issues, and the closing_app() method in window.py has complex teardown logic that could fail

[kimocoder]

panic: runtime error: invalid memory address or nil pointer dereference
...
github.com/ollama/ollama/server.(*blobDownload).release(...)
github.com/ollama/ollama/server.(*blobDownload).Wait(...)
github.com/ollama/ollama/server.downloadBlob(...)
github.com/ollama/ollama/server.PullModel(...)

Crashes when pulling on start

[LokiFawkes]

Same, but I find it happens particularly with fast models, like Qwen3 Coder, when they write large messages.
It gives me the Gtk and Pango assertion errors after a while of receiving tokens in quick succession.

INFO    [main.py | main] Alpaca version: 8.4.3
MESA-INTEL: warning: ../src/intel/vulkan_hasvk/anv_formats.c:790: FINISHME: support more multi-planar formats with DRM modifiers
MESA-INTEL: warning: ../src/intel/vulkan_hasvk/anv_formats.c:759: FINISHME: support YUV colorspace with DRM format modifiers

(python3:2): Gtk-CRITICAL **: 18:27:15.999: gtk_text_attributes_ref: assertion 'values != NULL' failed

(python3:2): Pango-CRITICAL **: 18:27:15.999: pango_layout_new: assertion 'context != NULL' failed

Don't worry about the mesa-intel stuff, I run Alpaca on a laptop and Ollama on a separate machine.

Nov 29 18:06:38 lokis-macbook-pro systemd[1192]: Started app-com.jeffser.Alpaca@5b9710e72f4a42b1b2b0da91d0344da9.service - Alpaca.
Nov 29 18:06:38 lokis-macbook-pro systemd[1192]: Started app-flatpak-com.jeffser.Alpaca-4945.scope.
Nov 29 18:06:43 lokis-macbook-pro flatpak[4958]: INFO        [main.py | main] Alpaca version: 8.4.3
Nov 29 18:11:31 lokis-macbook-pro kernel: alpaca[4958]: segfault at 4 ip 00007e78240b6eb4 sp 00007ffff0b25920 error 4 in libgtk-4.so.1.2000.3[2b6eb4,7e7823ee8000+519000] likely on CPU 1 (core 1, socket 0)
Nov 29 18:11:37 lokis-macbook-pro systemd-coredump[5083]: Process 4958 (alpaca) of user 1000 dumped core.
Nov 29 18:11:38 lokis-macbook-pro drkonqi-coredump-processor[5084]: "/usr/bin/python3.13" 4958 "/var/lib/systemd/coredump/core.alpaca.1000.828ac58d2af3446494a3e66b44557764.4958.1764461491000000.zst"
Nov 29 18:11:38 lokis-macbook-pro systemd[1192]: app-com.jeffser.Alpaca@5b9710e72f4a42b1b2b0da91d0344da9.service: Main process exited, code=exited, status=139/n/a
Nov 29 18:11:38 lokis-macbook-pro systemd[1192]: app-com.jeffser.Alpaca@5b9710e72f4a42b1b2b0da91d0344da9.service: Failed with result 'exit-code'.
Nov 29 18:11:38 lokis-macbook-pro systemd[1192]: app-flatpak-com.jeffser.Alpaca-4945.scope: Consumed 30.699s CPU time.
Nov 29 18:12:04 lokis-macbook-pro systemd[1192]: Started app-flatpak-com.jeffser.Alpaca-5217.scope.
Nov 29 18:13:30 lokis-macbook-pro kernel: alpaca[5228]: segfault at 4 ip 000075c9150b6eb4 sp 00007ffe6f61c080 error 4 in libgtk-4.so.1.2000.3[2b6eb4,75c914ee8000+519000] likely on CPU 1 (core 1, socket 0)
Nov 29 18:13:37 lokis-macbook-pro systemd-coredump[5287]: Process 5228 (alpaca) of user 1000 dumped core.
Nov 29 18:13:38 lokis-macbook-pro drkonqi-coredump-processor[5288]: "/usr/bin/python3.13" 5228 "/var/lib/systemd/coredump/core.alpaca.1000.828ac58d2af3446494a3e66b44557764.5228.1764461610000000.zst"
Nov 29 18:13:38 lokis-macbook-pro systemd[1192]: app-flatpak-com.jeffser.Alpaca-5217.scope: Consumed 23.598s CPU time.
Nov 29 18:25:14 lokis-macbook-pro systemd[1192]: Started app-flatpak-com.jeffser.Alpaca-5677.scope.
Nov 29 18:27:15 lokis-macbook-pro kernel: alpaca[5694]: segfault at 4 ip 000077f5b92b6eb4 sp 00007fff305ffe80 error 4 in libgtk-4.so.1.2000.3[2b6eb4,77f5b90e8000+519000] likely on CPU 2 (core 0, socket 0)
Nov 29 18:27:22 lokis-macbook-pro systemd-coredump[5758]: Process 5694 (alpaca) of user 1000 dumped core.
Nov 29 18:27:22 lokis-macbook-pro drkonqi-coredump-processor[5759]: "/usr/bin/python3.13" 5694 "/var/lib/systemd/coredump/core.alpaca.1000.828ac58d2af3446494a3e66b44557764.5694.1764462435000000.zst"
Nov 29 18:27:22 lokis-macbook-pro systemd[1192]: app-flatpak-com.jeffser.Alpaca-5677.scope: Consumed 20.598s CPU time.