When I called make, I got this error:
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
The issue is that High Sierra messes up Xcode. To fix it, type xcode-select --install (more info here), then you can run make.
I suggest adding a note about this to the Readme.