message: Update Mac prerequisites
  Cr-Commit-Position: refs/heads/main@{#34831}
diff: @@ -36,8 +36,13 @@ suppported configuration however.
  ## macOS
  -Xcode 9 or higher is required. Latest Xcode is recommended to be able to build
  -all code.
  +Xcode 12 or higher is required. Latest Xcode is recommended to be able to build
  +all code. You may use `xcode-select --install` to install it.
  +
  +Absence of Xcode will cause errors like:
  +```
  +xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
  +```
  ## Android
  