If you have any interest in compiling 32-bit applications, you'll need to downgrade or set up another machine with High Sierra. Mojave will still run 32-bit app

If you have any interest in compiling 32-bit applications, you'll need to downgrade or set up another machine with High Sierra. Mojave will still run 32-bit applications with a warning, but it can not build for i386, will build only for x86_64.