Compilation fails when using System.ValueTuple

Question

1. VS 2017 version 15.3.2
2. project targets framework 4.6.2
3. Installed nuget package System.ValueTuple latest stable 4.4.0
4. Use value tuple, no error shown in editor
5. Run compile step, no errors in error window, only output window shows compilation failed and actual error messages

Invalid token '(' in class, struct, or interface member declaration

What is going on?

I created a branch in git from this one, and everything works fine. I merge changes back, compilation fails. I tried uninstalling package and re-installing, same thing.

Answer 1

From over here:

You should update Microsoft.Net.Compilers package to (at least) version 2.0.