UE4 unable to detect Xcode on Macbook

I’ve been having some major problems getting UE4 to run on my Macbook lately. I keep getting this pesky popup telling me Unreal can’t detect Xcode on my machine.

None of my projects are C++, I’ve been using Blueprint the whole time. If I’m not using C++, then why the hell is Unreal asking me to use Xcode? Does Unreal really need it, regardless of wether the project is Blueprint or C++?
Lastly, I’d like to note that I’m trying to save on storage space, so I’m running UE4 & Xcode off of an external Lacie hard drive. Perhaps that’s the issue?
I’m at a total loss here, any help is greatly appreciated.

sudo xcode-select -s /Applications/Xcode.app/Contents/Developer