Update Vulkan SDK setup in CI workflow for Linux builds.

Enhance Vulkan SDK configuration by dynamically handling sysroot paths, setting explicit include and library directories, and refining CMake arguments, ensuring better compatibility and diagnostics.

Author: gpx1000

.github/workflows/simple_engine_ci.yml

@@ -132,9 +132,39 @@ jobs:
             exit 1
           fi
 
-          echo "VULKAN_SDK=$VULKAN_SDK_PATH" >> "$GITHUB_ENV"
-          echo "$VULKAN_SDK_PATH/bin" >> "$GITHUB_PATH"
-          echo "CMAKE_PREFIX_PATH=$VULKAN_SDK_PATH" >> "$GITHUB_ENV"
+          # Most LunarG tarballs have the actual sysroot under `x86_64/`.
+          # We want `VULKAN_SDK` to point at the directory that contains `include/`, `lib/`, `bin/`.
+          SDK_SYSROOT="$VULKAN_SDK_PATH"
+          if [ -d "$VULKAN_SDK_PATH/x86_64" ]; then
+            SDK_SYSROOT="$VULKAN_SDK_PATH/x86_64"
+          fi
+
+          echo "VULKAN_SDK=$SDK_SYSROOT" >> "$GITHUB_ENV"
+          echo "$SDK_SYSROOT/bin" >> "$GITHUB_PATH"
+          echo "CMAKE_PREFIX_PATH=$SDK_SYSROOT" >> "$GITHUB_ENV"
+
+          # Force CMake's FindVulkan to use the SDK headers/libs instead of runner system headers.
+          echo "Vulkan_INCLUDE_DIR=$SDK_SYSROOT/include" >> "$GITHUB_ENV"
+          if [ -f "$SDK_SYSROOT/lib/libvulkan.so" ]; then
+            echo "Vulkan_LIBRARY=$SDK_SYSROOT/lib/libvulkan.so" >> "$GITHUB_ENV"
+          elif [ -f "$SDK_SYSROOT/lib/libvulkan.so.1" ]; then
+            echo "Vulkan_LIBRARY=$SDK_SYSROOT/lib/libvulkan.so.1" >> "$GITHUB_ENV"
+          fi
+
+      - name: Vulkan SDK diagnostics (Linux)
+        if: runner.os == 'Linux'
+        shell: bash
+        run: |
+          set -euo pipefail
+          echo "VULKAN_SDK=$VULKAN_SDK"
+          echo "Vulkan_INCLUDE_DIR=${Vulkan_INCLUDE_DIR:-}"
+          echo "Vulkan_LIBRARY=${Vulkan_LIBRARY:-}"
+          if [ -f "${VULKAN_SDK}/include/vulkan/vulkan.hpp" ]; then
+            echo "Using SDK vulkan.hpp at: ${VULKAN_SDK}/include/vulkan/vulkan.hpp"
+            head -n 5 "${VULKAN_SDK}/include/vulkan/vulkan.hpp" || true
+          else
+            echo "WARNING: SDK vulkan.hpp not found under ${VULKAN_SDK}/include/vulkan/vulkan.hpp" >&2
+          fi
 
       # Use the engine's dependency install scripts instead of calling vcpkg directly in CI.
       - name: Bootstrap vcpkg (Windows)
@@ -179,11 +209,21 @@ jobs:
       - name: Configure (Linux)
         if: runner.os == 'Linux'
         shell: bash
-        run: >
-          cmake -S . -B build -G Ninja
-          -DCMAKE_BUILD_TYPE=Release
-          -DCMAKE_C_COMPILER=clang
-          -DCMAKE_CXX_COMPILER=clang++
+        run: |
+          set -euo pipefail
+          extra_args=()
+          if [ -n "${Vulkan_INCLUDE_DIR:-}" ]; then
+            extra_args+=("-DVulkan_INCLUDE_DIR=${Vulkan_INCLUDE_DIR}")
+          fi
+          if [ -n "${Vulkan_LIBRARY:-}" ]; then
+            extra_args+=("-DVulkan_LIBRARY=${Vulkan_LIBRARY}")
+          fi
+
+          cmake -S . -B build -G Ninja \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DCMAKE_C_COMPILER=clang \
+            -DCMAKE_CXX_COMPILER=clang++ \
+            "${extra_args[@]}"
 
       - name: Build
         run: cmake --build build --target SimpleEngine --parallel 4