diff --git a/.github/workflows/build-reusable.yml b/.github/workflows/build-reusable.yml
index e6a381e..8c0f31d 100644
--- a/.github/workflows/build-reusable.yml
+++ b/.github/workflows/build-reusable.yml
@@ -253,6 +253,55 @@ jobs:
           if [[ "${{ matrix.os }}" == "ubuntu-22.04" ]]; then
             echo "🔍 [HANG DEBUG] Ubuntu 22.04 detected - enabling enhanced process monitoring"
 
+            # Create Python script to inject stack trace dumping into pytest
+            cat > debug_pytest.py << 'EOF'
+            import signal
+            import faulthandler
+            import threading
+            import time
+            import sys
+            import traceback
+
+            def setup_hang_detection():
+                """Setup signal handlers and faulthandler for hang detection"""
+                # Enable faulthandler for automatic stack dumps
+                faulthandler.enable()
+
+                def dump_all_stacks(signum, frame):
+                    print(f"\n🔥 [HANG DEBUG] SIGNAL {signum} - DUMPING ALL THREAD STACKS:")
+                    faulthandler.dump_traceback()
+                    # Also dump current frames manually
+                    for thread_id, frame in sys._current_frames().items():
+                        print(f"\n📍 Thread {thread_id}:")
+                        traceback.print_stack(frame)
+
+                def periodic_stack_dump():
+                    """Periodically dump stacks to catch hang location"""
+                    time.sleep(300)  # Wait 5 minutes
+                    print(f"\n⏰ [HANG DEBUG] Periodic stack dump at {time.time()}:")
+                    for thread_id, frame in sys._current_frames().items():
+                        print(f"\n📍 Thread {thread_id}:")
+                        traceback.print_stack(frame)
+                    time.sleep(300)  # Wait another 5 minutes if still running
+                    print(f"\n⚠️ [HANG DEBUG] Final stack dump at {time.time()} (likely hanging):")
+                    faulthandler.dump_traceback()
+
+                # Register signal handlers for external debugging
+                signal.signal(signal.SIGUSR1, dump_all_stacks)
+                signal.signal(signal.SIGUSR2, dump_all_stacks)
+
+                # Start periodic dumping thread
+                dump_thread = threading.Thread(target=periodic_stack_dump, daemon=True)
+                dump_thread.start()
+
+            if __name__ == "__main__":
+                setup_hang_detection()
+                # Re-exec pytest with debugging enabled
+                import subprocess
+                result = subprocess.run([sys.executable, "-m", "pytest"] + sys.argv[1:])
+                sys.exit(result.returncode)
+            EOF
+
             # Pre-test state
             echo "📊 [HANG DEBUG] Pre-test process state:"
             ps aux | grep -E "(python|embedding|zmq)" | grep -v grep || echo "No relevant processes"
@@ -307,6 +356,8 @@ jobs:
                     stable_count=$((stable_count + 1))
                     if [ $stable_count -ge 6 ]; then  # 30 seconds of low CPU
                       echo "⚠️ [EXTERNAL] $(date): Process appears hung - CPU stable at ${current_cpu}% for 30s"
+                      echo "🔍 [EXTERNAL] $(date): Sending SIGUSR1 to dump stack traces..."
+                      kill -USR1 $pytest_pid 2>/dev/null || echo "Failed to send signal"
                     fi
                   else
                     stable_count=0
@@ -341,7 +392,7 @@ jobs:
             timeout --preserve-status --signal=TERM --kill-after=30 600 bash -c '
               echo "▶️ [HANG DEBUG] Pytest starting at: $(date)"
               # Force unbuffered output and immediate flush
-              stdbuf -o0 -e0 pytest tests/ -v --tb=short --maxfail=5 -x -s 2>&1 | while IFS= read -r line; do
+              stdbuf -o0 -e0 python debug_pytest.py tests/ -v --tb=short --maxfail=5 -x -s 2>&1 | while IFS= read -r line; do
                 printf "%s [PYTEST] %s\n" "$(date +"%H:%M:%S")" "$line"
                 # Force flush after each line
                 sync