Apparently, the .uplugin SemVersion for the Waste Shielding dependency is using an invalid operator for defining the range and SML complains about it being unable to de-sugar the range (as it's using &&).
From what I've seen, if it's intended to only support versions 3.3.X and up (but excluding) 3.4.0, the correct SemVersion should be "~3.3.0" for Waste Shielding (instead of the "^3.3.0 && <3.4.0" which is using right now).