             ],
             sources: ["realm/object-store"],
             publicHeadersPath: "realm/object-store",
-            cxxSettings: [
+            cxxSettings: ([
                 .define("REALM_ENABLE_SYNC", to: "1"),
                 .define("REALM_PLATFORM_APPLE", to: "1", .when(platforms: [.macOS, .iOS, .tvOS, .watchOS])),
                 .headerSearchPath("realm/object-store")
-            ] + cxxSettings),
+            ] + cxxSettings) as [CXXSetting]),
         .target(
             name: "ObjectStoreTests",
             dependencies: ["ObjectStore", "SyncServer"],

            name: "SyncServer",
            dependencies: ["SyncClient"],
            path: "src",
            exclude: [
                "realm/sync/crypto_server_openssl.cpp",
            ] + syncCommandSources,
            sources: syncServerSources,
            publicHeadersPath: "realm/sync/impl", // hack
            cxxSettings: cxxSettings,

            name: "SyncClient",
            dependencies: ["Storage"],
            path: "src",
            exclude: ([
                "realm/sync/crypto_server_openssl.cpp",
            ] + syncCommandSources + syncServerSources) as [String],
            sources: [
                "realm/sync",
                "realm/util/network.cpp",
