stdlib.h file not found and macOS SDK package installer also not found
Apple has an installer for C++ libraries you can install.

xcode-select --install


If you have Xcode installed (or don't mind downloading it from the App Store) run it to validate all the command line tools are installed as well as additional tools. Lastly, once these are installed, check for normal software updates to ensure the command line updates are applied.

You might need to look at the output of the build script to see if you just need to reset the default location of the compile tools:

xcode-select --reset