fix: prefer compiler runtimes in Windows packages

scripts/package-native-runtime.sh

@@ -458,6 +458,16 @@ if [[ "$runtime_os" == "windows" ]]; then
     for library in "${runtime_libraries[@]}"; do
         dependency_args+=(--search-dir "$(dirname "$library")")
     done
+    # The Vulkan SDK can contain an older MinGW runtime. Let the dependency
+    # resolver discover the compiler runtime before searching SDK directories.
+    # This also keeps CPU packages self-contained when their DLLs use MinGW.
+    if [[ "$BACKEND" == "cpu" || "$BACKEND" == "vulkan" ]]; then
+        mingw_compiler="${MINGW_CXX:-${CXX:-g++}}"
+        mingw_compiler_path="$(command -v "$mingw_compiler" || true)"
+        if [[ -n "$mingw_compiler_path" ]]; then
+            dependency_args+=(--search-dir "$(dirname "$mingw_compiler_path")")
+        fi
+    fi
     for dependency_root in CUDA_PATH ROCM_PATH VULKAN_SDK; do
         dependency_dir="${!dependency_root:-}"
         if [[ -n "$dependency_dir" ]]; then

scripts/tests/test_windows_native_runtime_deps.py

@@ -8,6 +8,7 @@
 import subprocess
 import tempfile
 import unittest
+from unittest import mock
 
 
 SCRIPT = pathlib.Path(__file__).parents[1] / "windows-native-runtime-deps.py"
@@ -88,6 +89,38 @@ def test_collects_mingw_dependency_closure(self):
             )
             DEPS.verify_dependencies(lib_dir)
 
+    def test_compiler_runtime_wins_over_vulkan_sdk_runtime(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root = pathlib.Path(directory)
+            lib_dir = root / "artifact" / "lib"
+            compiler_dir = root / "mingw" / "bin"
+            sdk_dir = root / "vulkan" / "Bin"
+            lib_dir.mkdir(parents=True)
+            compiler_dir.mkdir(parents=True)
+            sdk_dir.mkdir(parents=True)
+            write_pe(lib_dir / "ggml-vulkan.dll", ["libstdc++-6.dll"])
+            write_pe(compiler_dir / "libstdc++-6.dll", ["KERNEL32.dll"])
+            write_pe(sdk_dir / "libstdc++-6.dll", ["missing-sdk-runtime.dll"])
+
+            with mock.patch.object(
+                DEPS.shutil, "which", return_value=str(compiler_dir / "g++.exe")
+            ), mock.patch.dict(
+                DEPS.os.environ,
+                {
+                    "PATH": str(sdk_dir),
+                    "VULKAN_SDK": str(root / "vulkan"),
+                },
+                clear=False,
+            ):
+                copied = DEPS.collect_dependencies(lib_dir, [])
+
+            self.assertEqual([path.name for path in copied], ["libstdc++-6.dll"])
+            self.assertEqual(
+                (lib_dir / "libstdc++-6.dll").read_bytes(),
+                (compiler_dir / "libstdc++-6.dll").read_bytes(),
+            )
+            DEPS.verify_dependencies(lib_dir)
+
     def test_verification_rejects_missing_non_system_dependency(self):
         with tempfile.TemporaryDirectory() as directory:
             lib_dir = pathlib.Path(directory)

scripts/windows-native-runtime-deps.py

@@ -136,16 +136,21 @@ def is_host_dll(name: str) -> bool:
 
 def default_search_dirs() -> list[pathlib.Path]:
     candidates: list[pathlib.Path] = []
-    vulkan_sdk = os.environ.get("VULKAN_SDK")
-    if vulkan_sdk:
-        candidates.extend(
-            [pathlib.Path(vulkan_sdk) / "Bin", pathlib.Path(vulkan_sdk) / "Bin32"]
-        )
+    for compiler in ("g++", "gcc"):
+        compiler_path = shutil.which(compiler)
+        if compiler_path:
+            candidates.append(pathlib.Path(compiler_path).parent)
+            break
     candidates.extend(
         pathlib.Path(entry)
         for entry in os.environ.get("PATH", "").split(os.pathsep)
         if entry
     )
+    vulkan_sdk = os.environ.get("VULKAN_SDK")
+    if vulkan_sdk:
+        candidates.extend(
+            [pathlib.Path(vulkan_sdk) / "Bin", pathlib.Path(vulkan_sdk) / "Bin32"]
+        )
     return candidates