debug: add gdb backtrace on segfault for embed tests

Author: Qard

.github/workflows/build.yml

@@ -225,7 +225,24 @@ jobs:
           echo "LLVM_CONFIG_PATH=${{ runner.temp }}/llvm-${{ env.clang }}/bin/llvm-config" >> $GITHUB_ENV
 
       - name: Test with embed feature
-        run: cargo test --workspace --release --features closure,embed,anyhow --no-fail-fast
+        run: |
+          sudo apt-get update && sudo apt-get install -y gdb
+          sudo sysctl -w kernel.core_pattern='core.%e.%p'
+          ulimit -c unlimited
+          echo "Core pattern: $(cat /proc/sys/kernel/core_pattern)"
+          echo "Ulimit -c: $(ulimit -c)"
+          cargo test --workspace --release --features closure,embed,anyhow --no-fail-fast || \
+            (echo "Test failed, looking for core dumps..."; ls -la core.* 2>/dev/null || echo "No core files found"; \
+            for core in core.*; do \
+              if [ -f "$core" ]; then \
+                echo "Found core: $core"; \
+                exe=$(find target/release/deps -type f -executable -name "sapi_tests-*" ! -name "*.d" | head -1); \
+                if [ -n "$exe" ]; then \
+                  echo "Using executable: $exe"; \
+                  gdb -batch -ex "thread apply all bt" "$exe" "$core"; \
+                fi; \
+              fi; \
+            done; exit 1)
 
   build-musl:
     name: musl / ${{ matrix.php }} / ${{ matrix.phpts[1] }}
@@ -239,7 +256,7 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v5
-      - name: Setup DockerX 
+      - name: Setup DockerX
         uses: docker/setup-buildx-action@v3
       - name: Build
         uses: docker/build-push-action@v6
@@ -267,4 +284,4 @@ jobs:
             -v $(pwd):/workspace \
             -w /workspace \
             extphprs/ext-php-rs:musl-${{ matrix.php }}-${{ matrix.phpts[1] }} \
-            test --workspace --release --features closure,anyhow,runtime --no-fail-fast
+            test --workspace --release --features closure,anyhow,runtime --no-fail-fast