The goal is to run React Native Apps as a MacOS App, using the released Mac Catalyst technology.
The error occurs with a blank React Native Project (0.61.2), when building it for MacOS.
The app runs for iOS and iPadOS.
React Native version:
System:
OS: macOS 10.15
CPU: (8) x64 Intel(R) Core(TM) i7-4750HQ CPU @ 2.00GHz
Memory: 90.74 MB / 8.00 GB
Shell: 5.0.11 - /usr/local/bin/bash
Binaries:
Node: 10.16.3 - /usr/local/bin/node
npm: 6.11.3 - /usr/local/bin/npm
Watchman: 4.9.0 - /usr/local/bin/watchman
SDKs:
iOS SDK:
Platforms: iOS 13.2, DriverKit 19.0, macOS 10.15, tvOS 13.2, watchOS 6.1
Android SDK:
API Levels: 28, 29
Build Tools: 28.0.3, 29.0.2
System Images: android-28 | Google APIs Intel x86 Atom, android-28 | Google APIs Intel x86 Atom_64, android-29 | Google APIs Intel x86 Atom
IDEs:
Android Studio: 3.5 AI-191.8026.42.35.5791312
Xcode: 11.2/11B44 - /usr/bin/xcodebuild
npmPackages:
react: 16.9.0 => 16.9.0
react-native: 0.61.2 => 0.61.2
npmGlobalPackages:
create-react-native-app: 2.0.2
react-native-cli: 2.0.1
react-native-macos-cli: 2.0.1


Building without errors and run the MacOS app.
Undefined symbols for architecture x86_64:
"_OBJC_CLASS_$_RCTSRWebSocket", referenced from:
l_OBJC_$_CATEGORY_RCTSRWebSocket_$_React in libReact-Core.a(RCTWebSocketModule.o)
objc-class-ref in libReact-Core.a(RCTWebSocketModule.o)
objc-class-ref in libReact-Core.a(RCTReconnectingWebSocket.o)
objc-class-ref in libReact-Core.a(RCTWebSocketExecutor.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

https://github.com/facebook/react-native/issues/17320
https://github.com/facebook/react-native/issues/14925
Also we found out that the file React-RCTWebSocket.podspec is still on version 0.60.5:
{
"name": "React-RCTWebSocket",
"version": "0.60.5", ... }
We could solve the issue with following solution:
https://github.com/react-native-community/discussions-and-proposals/issues/131#issuecomment-544190522
Thanks for linking the solution, that worked for me! 馃檪
not work for me in iPhoneX simulator.
I am getting:
Undefined symbols for architecture x86_64:
"___darwin_check_fd_set_overflow", referenced from:
_RAND_poll in libcrypto.a(rand_unix.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
After upgrade to 0.63.3
@ghasemikasra39 i'm getting the same issue with you, do you find any solution for it?
Yes, same. Getting error on 0.63.3 with new fresh project
Undefined symbol: ___darwin_check_fd_set_overflow
Anyone can please help for this
@ghasemikasra39 i'm getting the same issue with you, do you find any solution for it?
Upgrade Xcode to the latest version. It's fixed on ios 14
Yes, same. Getting error on 0.63.3 with new fresh project
Undefined symbol: ___darwin_check_fd_set_overflowAnyone can please help for this
Upgrade Xcode to the latest version. It's fixed on ios 14
I'm getting the same error after upgrading to RN 0.63.3 from 0.62
@ghasemikasra39 Do you mean Xcode 12 GM seed ?
I'm getting the same error after upgrading to RN 0.63.3 from 0.62
@ghasemikasra39 Do you mean Xcode 12 GM seed ?
Yes, Upgrade your MacOS to latest version first to be able tp upgrade Xcode to v12. Then you have ios 14 on your simulators and everything works fine
I was with Xcode 11.3.1 on Mojave 10.14.6, got error after pod updating an existing project.
Solved it by installing Xcode 11.7 here https://developer.apple.com/download/more/ and edit LSMinimumSystemVersion in info.plist file.
Upgrade Xcode to the latest version. It's fixed on ios 14
Yes, this solved my issues, now same project, React Native 0.63.3 is running fine in XCode 12.0.1
I am using Xcode 11.3.1, react native 0.63. I also encountered the same issue while I am integrating Facebook SDK. Is there any other solution other than upgrading the Xcode version? Thank you
I was with Xcode 11.3.1 on Mojave 10.14.6, got error after pod updating an existing project.
Solved it by installing Xcode 11.7 here https://developer.apple.com/download/more/ and editLSMinimumSystemVersionin info.plist file.
Hey, What exactly you edit in LSMinimumSystemVersion?
I was with Xcode 11.3.1 on Mojave 10.14.6, got error after pod updating an existing project.
Solved it by installing Xcode 11.7 here https://developer.apple.com/download/more/ and editLSMinimumSystemVersionin info.plist file.Hey, What exactly you edit in
LSMinimumSystemVersion?
Just changed it to 10.14 as Mojave is 10.14
I degraded the react-native version from 0.63 to 0.61 and the problem got solved.
Also make sure you cd ios && pod install when you upgrade RN or any other dependency ;)
Most helpful comment
Yes, same. Getting error on 0.63.3 with new fresh project
Anyone can please help for this