not sure this is needed, but better windows build support

build.zig

@@ -6,7 +6,7 @@ const std = @import("std");
 // for defining build steps and express dependencies between them, allowing the
 // build runner to parallelize the build automatically (and the cache system to
 // know when a step doesn't need to be re-run).
-pub fn build(b: *std.Build) void {
+pub fn build(b: *std.Build) !void {
     // Standard target options allow the person running `zig build` to choose
     // what target to build for. Here we do not override the defaults, which
     // means any target is allowed, and the default is native. Other options
@@ -67,7 +67,11 @@ pub fn build(b: *std.Build) void {
         patch_cmd.addArg(s.orig);
         patch_cmd.addArg(s.new);
     }
-    patch_cmd.addFileArg(upstream.path("src/utilities.c"));
+    const util_src = try std.fs.path.join(b.allocator, &.{
+        "src",
+        "utilities.c",
+    });
+    patch_cmd.addFileArg(upstream.path(util_src));
     patch_cmd.step.dependOn(&download_link_step.step);
 
     const lib = b.addLibrary(.{