When invoking ghc directly on macOS, you'll need to give it -dynamic - otherwise, compiling fails with something like
Undefined symbols for architecture x86_64:
"_OBJC_CLASS_$_NSURL", referenced from:
objc-class-ref in libHSjsaddle-wkwebview-0.9.4.0-2SHufpCZa9lIA8lareALCO.a(WKWebView.o)
ld: symbol(s) not found for architecture x86_64
and -threaded - otherwise running the binary yields
user error (RTS doesn't support multiple OS threads (use ghc -threaded when linking))