Fix Xcode 26 build: suppress deprecated-declarations + BABYLON_USE_SYSTEM_CMAKE env var (#726)

* Fix Xcode 26 build: suppress deprecated-declarations for Clang targets

wstring_convert<codecvt_utf8_utf16> is deprecated in C++17 and the
BabylonNative cmakeextensions build helper adds -Werror to all Clang
targets, turning this deprecation into a hard build error on
Xcode 26+ / Clang 20+.

Add -Wno-deprecated-declarations via add_compile_options for Clang/
AppleClang builds so the project compiles cleanly while all other
-Werror checks remain enforced.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add BABYLON_USE_SYSTEM_CMAKE env var and update version table

- postinstall.js: add BABYLON_USE_SYSTEM_CMAKE=1 env variable that
  bypasses the npm-bundled cmake-runtime package and uses whatever
  cmake is found on PATH (Homebrew, system install, etc.)
- README: document the new BABYLON_USE_SYSTEM_CMAKE variable in the
  iOS CMake configuration section
- README: add BabylonReactNative 2.0.2 entry to the Platform Native
  Packages version table (requires Babylon.js 9.0.0, BabylonNative 887a044)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Update BabylonNative to ce2edf08 and fix README commit hash format

- Package/gulpfile.js: update COMMIT_ID to latest BabylonNative master
  commit ce2edf0851e0c8483559832a4f8eb9d39c6b2f53
- README.md: use full 40-character commit hash for the 2.0.2 row to
  match the format of existing rows in the Platform Native Packages table

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: CedricGuillemet

Modules/@babylonjs/react-native/README.md

@@ -34,6 +34,11 @@ To disable post install CMake generation, set this variable before running `npm
 export BABYLON_NO_CMAKE_POSTINSTALL=1
 ```
 
+To use the system cmake (e.g. a Homebrew or system install) instead of the cmake bundled in the npm package, set this variable before running `npm install`:
+```
+export BABYLON_USE_SYSTEM_CMAKE=1
+```
+
 ### Plugins selection
 
 Plugins can be disabled at build time. They are all enabled by default and disabling is done with environment variables:
@@ -56,6 +61,7 @@ Babylon.js minimal version:
 
 |BabylonReactNative version | Babylon.js version | BabylonNative commit |
 | ----------- | ------------------------ | --- |
+|2.0.2 | 9.0.0 | ce2edf0851e0c8483559832a4f8eb9d39c6b2f53
 |2.0.0 | 8.3.0 | 6c25966e8f8c0f3a0c13fdf77064f1bde790391f
 
 

Modules/@babylonjs/react-native/ios/CMakeLists.txt

@@ -19,6 +19,12 @@ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -x objective-c++")
 
+# wstring_convert and codecvt_utf8_utf16 are deprecated in C++17; prevent this from
+# being treated as a hard error so the build succeeds on Xcode 26+ / Clang 20+.
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+    add_compile_options(-Wno-deprecated-declarations)
+endif()
+
 set(BABYLON_NATIVE_PLUGIN_NATIVEXR 1)
 if(DEFINED ENV{BABYLON_NATIVE_PLUGIN_NATIVEXR})
     set(BABYLON_NATIVE_PLUGIN_NATIVEXR $ENV{BABYLON_NATIVE_PLUGIN_NATIVEXR})

Modules/@babylonjs/react-native/postinstall.js

@@ -2,6 +2,11 @@ const os = require("os");
 const path = require("path");
 
 function getCmakeExecutable() {
+  // When BABYLON_USE_SYSTEM_CMAKE=1, skip the npm cmake package and use whatever
+  // cmake is found on PATH (e.g. a Homebrew or system install).
+  if (process.env.BABYLON_USE_SYSTEM_CMAKE === '1') {
+    return 'cmake';
+  }
   try {
     // cmake-runtime ships the cmake binary; resolve it directly to avoid
     // relying on npx or PATH.

Package/gulpfile.js

@@ -230,7 +230,7 @@ const createPackage = async () => {
   exec('npm pack', 'Assembled');
 };
 
-const COMMIT_ID = '887a0446c2ce5d379d931d802071cf6f9e008c6a';
+const COMMIT_ID = 'ce2edf0851e0c8483559832a4f8eb9d39c6b2f53';
 const ZIP_URL = `https://github.com/BabylonJS/BabylonNative/archive/${COMMIT_ID}.zip`;
 const TARGET_DIR = path.resolve(__dirname, '../Modules/@babylonjs/react-native/shared/BabylonNative');
 const ZIP_PATH = path.join(TARGET_DIR, `${COMMIT_ID}.zip`);