Problems with glog (config.h missing) and gflags/gflags.h on Xcode 10

[WesSouza]

Trying to build the initial React Native project is not working on Xcode 10 on Mojave, tested on two machines and had slightly different issues both while compiling glog.

react-native init TestProject --version="0.56.0-rc.2"
cd TestProject
npm run start
react-native run-ios

Fails because 'config.h' file not found on mutex.h. Manually configuring and making glog from node_modules/react-native/third-party/glog-0.3.4 works, but then fails because 'gflags/gflags.h' file not found.

If I try to compile on Xcode 9.4, it also fails. The only thing that enabled me to build on either was:

1. rm -rf ~/.rncache/
2. rm -rf $PROJECT/node_modules/react-native/third-party/
3. Build on Xcode 9.4, passes. Quit Xcode.
4. Build on Xcode 10, passes.

It is very unstable though, stops working as soon as I reopen Xcode.

---

I've tested on another machine and had another issue with glog build:

checking for arm-apple-darwin-gcc... /Applications/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc -arch undefined_arch -isysroot /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.0.sdk
checking whether the C compiler works... no
configure: error: in `(..._/node_modules/react-native/third-party/glog-0.3.4':
configure: error: C compiler cannot create executables
See `config.log' for more details

config.log: https://pastebin.com/8M4ybuEp

This machine did not have Xcode installed before. I did install the Command Line Utils.

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