Have a Xamarin.Forms project with net standard 2 XF assembly driving UWP and iOS apps. Running XF v18.104.22.1688975 on Visual Studio Community 2017 15.9.4 on the latest Windows 10. Mac that is performing the build is running Mojave 10.14.1 and Visual Studio Mac 7.7.2 (Build 21).
UWP application builds and runs with no problems. iOS build was running without any problems up to about two weeks ago.
Now the iOS build throws out several MT0136 warnings for assemblies that are referenced by the net standard assembly and then crashes out with MT2001 that tells me that encountered an error while processing references of the net standard 2 assembly. This is after the detection of the signing identity output and the linker setting is do not link (debug mode).
Any guidance is greatly appreciated. Note that I already tried common approaches involving deleting bin/obj directories and mac build cache cleanup.