Leon Chaewon Kong's dev blog

React Native - build commands failed: DoubleConversion-dummy.m normal x86_64 objective-c com.apple.compilers.llvm.clang.1_0.compiler

Build failure in debug. Build Succeeds in Xcode but Fails in terminal when running react-native run-ios.

Original Error:

Possible Solutions

Deleting Xcode Cache

rm -rf ~/Library/Developer/Xcode/DerivedData/*

In my case, it didn’t worked.

Using Legacy Build System

in xcodeproj

  1. Navigate to File > Project Settings > Build System.
  2. Change this to Legacy Build System.

In my case, it didn’t worked either. Some said that this issue isn’t about build system.

Cleaning Node Modules and iOS Build Directory

$ rm -rf node_modules
$ rm -f yarn.lock
$ yarn
$ rm -rf ios/build/*

This is the only solution that worked for me. After removing all node_modules and yarn.lock file, I removed all files and sub-directories under ios/build. Then, I ran react-native run-ios again, and it finally worked.