Title
Android 14/15 crash with Kivy + Buildozer: pthread_mutex_lock called on a destroyed mutex (SDLActivity)
Problem Description
I'm building a Python game using Kivy, packaged for Android via Buildozer and python-for-android. The app installs successfully, but crashes immediately on launch on Android 14 and 15 devices.
The crash log shows:
FORTIFY: pthread_mutex_lock called on a destroyed mutex (0x7eca402dc8)
Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid (hwuiTask1), pid (SDLActivity)
There’s no Python traceback—the crash appears to be native-level, possibly inside SDL2 or HWUI threads.
Environment
- OS: Ubuntu 24.04.3 LTS (x86_64)
- Python: 3.9.9
- Kivy: 2.3.0
- Buildozer: 1.5.0
- python-for-android: 2024.1.21 (latest GitHub)
- NDK: r25c
- Target API: 35
- Arch: arm64-v8a (also tested armeabi-v7a)
- Devices: Android 15 (also reproduced on Android 14)
What I Tried
- Forcing GLES2 backend
- Disabling multisamples
- Building only for arm64-v8a
- Updating
python-for-androidto latest GitHub version - Clean rebuild with
buildozer android clean
Buildozer.spec Highlights
requirements = python3==3.9.9,kivy==2.3.0,cython==0.29.33,ffpyplayer,jnius,sdl2==2.28.5,sdl2_ttf,sdl2_image,sdl2_mixer
android.api = 35
android.minapi = 23
android.ndk = 25c
android.ndk_api = 23
android.enable_androidx = True
android.permissions = INTERNET
android.archs = arm64-v8a
android.meta_data = android.opengl.eglVersion=0x00020000
main.py Startup Code
import os, sys
from kivy.config import Config
os.environ["KIVY_METRICS_DENSITY"] = "2"
os.environ["KIVY_GL_BACKEND"] = "gles2"
Config.set("graphics", "multisamples", "0")
Config.set("graphics", "gles_backend", "gles2")
Config.set("graphics", "resizable", True)
# ... rest of imports and app logic ...
Expected Behavior
App should launch and display the game screen. I’m targeting API 35 for Play Store compatibility.
Question
Has anyone encountered this pthread_mutex_lock crash on Android 14/15 with SDL2 or Kivy?
Could this be related to NDK threading, SDL2 version, or Android’s HWUI changes?
Any workaround or insight would be greatly appreciated!
Let me know if you'd like help posting this or want to add a minimal reproducible example. You’re nearly there—this version should get attention from the right devs.
