Info

The mozjs upgrade uses std::to_chars which Apple's libc++ marks unavailable below macOS 10.15. Backport branches (e.g. v7.0) targeting older macOS fail to compile. [2026/03/20 23:49:26.434] In file included from src/third_party/mozjs/platform/x86_64/macOS/build/Unified_cpp_js_src14.cpp:47: [2026/03/20 23:49:26.434] src/third_party/mozjs/extract/js/src/vm/JSAtomUtils.cpp:906:22: error: 'to_chars' is unavailable: introduced in macOS 10.15 [2026/03/20 23:49:26.434] auto result = std::to_chars(buf, buf + std::size(buf), index, 10); [2026/03/20 23:49:26.434] ^ [2026/03/20 23:49:26.434] /Applications/Xcode13.2.1.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.1.sdk/usr/include/c++/v1/charconv:401:1: note: 'to_chars' has been explicitly marked unavailable here [2026/03/20 23:49:26.434] to_chars(char* __first, char* __last, _Tp __value, int __base) [2026/03/20 23:49:26.435] ^ EVG Failing Patch Fix: MONGO_MOZJS_TO_CHARS compat macro in js/src/util/ToCharsCompat.h — portable fallback on macOS std::to_chars otherwise. Applied in mongodb-forks/spidermonkey.

Top User Comments

xgen-internal-githook commented on Thu, 30 Apr 2026 04:05:57 +0000: Author: {'name': 'Aditya Deshpande', 'email': 'aditya.deshpande@mongodb.com', 'username': 'aditya8061'} Message: SERVER-122483 Add std::to_chars compatibility for macOS GitOrigin-RevId: 116cdc3e37337ccb94003e9b25ec752309a1b63b Branch: v7.0.32 https://github.com/mongodb/mongo/commit/5c7cbed379b070da024933135d4ef786e473f228 xgen-internal-githook commented on Tue, 24 Mar 2026 23:25:51 +0000: Author: {'name': 'Aditya Deshpande', 'email': 'aditya.deshpande@mongodb.com', 'username': 'aditya8061'} Message: SERVER-122483 Add std::to_chars compatibility for macOS GitOrigin-RevId: c4b4639b7aa50813d4510473b7bea447bd98ef25 Branch: master https://github.com/mongodb/mongo/commit/f9be842af6a20342e31734ed54e522e1442ce1e2

Steps to Reproduce