Windows build (2)

.github/workflows/ci.yml

@@ -48,7 +48,7 @@ jobs:
           - ubuntu-24.04-arm
           - macos-15-intel
           - macos-14
-#           - windows-latest
+          - windows-latest
 #           - windows-11-arm
     steps:
       - name: Checkout

build.py

@@ -1,15 +1,78 @@
 import contextlib
 import shutil
+import sys
+import sysconfig
 import typing
 from pathlib import Path
 
-import pydust
-from pydust.build import build
+
+def _ensure_ld_library() -> None:
+    """
+    Pydust assumes LDLIBRARY is always set, but on Windows (especially in PEP 517 isolated builds) it may be None.
+    Provide a correct fallback.
+    """
+    if sys.platform != "win32":
+        return
+
+    if sysconfig.get_config_var("LDLIBRARY") is None:
+        sysconfig._CONFIG_VARS["LDLIBRARY"] = f"python{sys.version_info.major}{sys.version_info.minor}.lib"
+
+
+_ensure_ld_library()  # MUST happen before importing pydust
+
+
+import pydust  # noqa: E402
+from pydust import buildzig  # noqa: E402
+from pydust import config as pydust_config  # noqa: E402
+from pydust.build import build  # noqa: E402
+
+# Patch Windows path pydust bug in build.zig
+if sys.platform == "win32":
+
+    def _generate_build_zig(fileobj: typing.TextIO, conf=pydust_config):
+        b = buildzig.Writer(fileobj)
+
+        b.writeln('const std = @import("std");')
+        b.writeln('const py = @import("./pydust.build.zig");')
+        b.writeln()
+
+        with b.block("pub fn build(b: *std.Build) void"):
+            b.write(
+                """
+                const target = b.standardTargetOptionsQueryOnly(.{});
+                const optimize = b.standardOptimizeOption(.{});
+
+                const test_step = b.step("test", "Run library tests");
+
+                const pydust = py.addPydust(b, .{
+                    .test_step = test_step,
+                });
+                """
+            )
+
+            for ext_module in conf.ext_modules:
+                assert ext_module.limited_api, "Only limited_api is supported for now"
+                ext_module_root = str(ext_module.root).replace("\\", "/")  # fix for windows
+                b.write(
+                    f"""
+                    _ = pydust.addPythonModule(.{{
+                        .name = "{ext_module.name}",
+                        .root_source_file = b.path("{ext_module_root}"),
+                        .limited_api = {str(ext_module.limited_api).lower()},
+                        .target = target,
+                        .optimize = optimize,
+                    }});
+                    """
+                )
+
+    buildzig.generate_build_zig = _generate_build_zig
 
 
 @contextlib.contextmanager
 def ensure_ffi_location() -> typing.Iterator[None]:
-    """For some reason, `zig translate-c` is looking for `ffi.h` in the wrong location."""
+    """
+    For some reason, `zig translate-c` is looking for `ffi.h` in the wrong location.
+    """
     dst = Path("pydust/src/ffi.h")
     dst.parent.mkdir(parents=True, exist_ok=True)
     src = Path(pydust.__file__).parent / "src" / "ffi.h"