According to https://bugzilla.xamarin.com/show_bug.cgi?id=43695#c5 the NuGet 3.4 that ships with C8 in XS/VS maps the products to netstandard1.5. Apparently we have communicated publicly that we support netstandard1.6 (though I can't find a definite announcement, the https://blog.xamarin.com/net-standard-library-support-for-xamarin/ blog doesn't say which version).
We need to decide whether we should fix this by a) modifying the mapping in the NuGet XS ships or b) ignore it and wait until we roll out NuGet 3.5
I cannot find any explicit 1.6 confirmation but netstandard pages has it as 1.6 (if I decoded that correctly) and our blog post highlight 1.6 everywhere too.
Yes, we should definitely update NuGet before C8 release - ideally 3.5 if it's out, else 3.5 RC. NuGet 3.4.x has outdated netstandard support.
NuGet versions currently have the following .NETStandard mappings for the Xamarin frameworks:
NuGet 2.12 => .NETStandard 1.6
NuGet 3.4.3 => .NETStandard 1.5
NuGet 3.4.4 => .NETStandard 1.5
NuGet 3.5 rc1 => .NETStandard 1.7
Updating Xamarin Studio to NuGet 3.5 rc1 will most likely involve changes to the NuGet addin since I know of at least one breaking change to the NuGet API that was made in 3.4.4 so I expect there will be more in 3.5.
A less risky change would be to update the mappings in the build of NuGet 3.4.3 that ships with Xamarin Studio. This would mean Xamarin Studio would have different behaviour to NuGet 3.4 in Visual Studio.
Fixed in version 126.96.36.19939 (cycle8)
Author: Matt Ward
Commit: 4253fd7a57af6b461554335110f63188f477aaca (mono/monodevelop)