Need to determine which .NET Core SDK has which C# version enabled

[BillWagner]

We explain which C# version ships with which release of Visual Studio. @damtur raised this issue after a talk that he could not find that mapping for the versions that ship with .NET Core SDK versions. For example, which .NET SDK has C# 7.1? or 7.2? This make affect the dotnet CLI, as the compiler ships as a dotnet tool.

We need to make this more prominent if it is published. If not, we need to publish it more prominently.

/cc @richlander @jcouv @KathleenDollard

[jcouv]

Tagging @livarcocc for this

[BillWagner]

As a work around, you can add an error pragma to the source to print the version:

#error version

This cause the compiler to print its version (the compiler software version, not the project LangVersion) to the console. It also causes the build to fail.

[KathleenDollard]

I agree we need this.

Do we have a place in docs to put this?