How to fix the `iphoneos cannot be located` error in macOS

While installing React Native to run a project on iOS, I run into a problem.

I went into the project’s ios folder to run pod install as I was instructed to do.

But as I ran that command, I got a long error message back:

From this error I read the error: SDK "iphoneos" cannot be located.

That looked suspicious, right?

So I researched a bit and what fixed the problem was running the command

sudo xcode-select --switch /Applications/Xcode.app

Then running pod install again worked fine!