Hopefully this is the right place. If not, please let me know and I'll create this elsewhere.
I created a net .NET 4.7.2 class library project and tried to reference the System.Net.Http 4.3.3 NuGet package and the entire System.Net.Http namespace is missing. I can't reference HttpClient. I'm using PackageReference though I think packages.config is also broken. As soon as I change the library to .NET 4.7.1, it all works as expected.