I tried to run an existing react-native project on mac to create ios build but i've been getting into an unusual error as mentioned below. I don't know what RCT-Folly does as i am new to react-native but i think the error is related to RCT-Folly, I tried many other stack answers but couldn't solve it Here is a picture of the error

I have tried the other solution like creating a fresh projects and copying files, also tried reinstalling cocoapods, If there is some other thread that you guys think i should try please let me know Stuck at this for more than 3 days now!

Update: After downgrading react native version it is now showing this error:

CompileC /Users/admin/Desktop/MTM/mindToMindfull\ 2/ios/Build/Intermediates.noindex/Pods.build/Debug-iphonesimulator/React-Core.build/Objects-normal/x86_64/RCTJSThread.o /Users/admin/Desktop/MTM/mindToMindfull\ 2/node_modules/react-native/React/Base/RCTJSThread.m normal x86_64 objective-c com.apple.compilers.llvm.clang.1_0.compiler (in target 'React-Core' from project 'Pods')

CodePudding user response：

RCT-Folly is an iOS Cocoapod library. Try cleaning your project first. From the project root, run (for Yarn)

1. watchman watch-del-all && rm -f yarn.lock; rm -rf node_modules, then
2. yarn
3. cd ios && rm -rf ~/Library/Caches/CocoaPods Pods ~/Library/Developer/Xcode/DerivedData/; rm Podfile.lock; pod deintegrate; pod setup; pod install && cd ..
4. yarn ios

I haven't used npm in awhile. But for 2 and 4, use npm install and npx react-native run-ios

CodePudding user response：

Solved by downgrading react-native version 0.66.4 then installing pods and build was a success.