build: add cxx library path to rpath if its not a native path

build.zig

@@ -804,6 +804,28 @@ fn addCxxKnownPath(
     }
     exe.addObjectFile(.{ .cwd_relative = path_unpadded });
 
+    const resolved_path = fs.realpathAlloc(b.allocator, path_unpadded) catch path_unpadded;
+
+    if (std.mem.lastIndexOfScalar(u8, resolved_path, '/')) |path_end| {
+        const obj_dir = resolved_path[0..path_end];
+
+        const add_obj_dir = blk: {
+            const native_paths = NativePaths.detect(b.allocator, exe.target_info) catch {
+                break :blk true;
+            };
+
+            for (native_paths.lib_dirs.items) |lib_dir| {
+                if (mem.eql(u8, lib_dir, obj_dir))
+                    break :blk false;
+            }
+
+            break :blk true;
+        };
+
+        if (add_obj_dir)
+            exe.addLibraryPath(.{ .cwd_relative = obj_dir });
+    }
+
     // TODO a way to integrate with system c++ include files here
     // c++ -E -Wp,-v -xc++ /dev/null
     if (need_cpp_includes) {