Bug Assembly-CSharp.csproj created with <LangVersion>latest</LangVersion>, not currently used in Unity

I was wondering, why Unity screamed at me with

Code (CSharp):

1. error CS0136: A local or parameter named 't' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter
2.  

But my editor had nothing to say about this.
I searched internet for the problems with my IDEs (VSCode, Visual Studio For Mac)

At the end I discovered that since C# 8 version this error is no longer an error, and it's possible to code that way.

My IDEs used "latest" version of language available for my system, which happened to be C# 8

But Unity supports C# 7

I found that the culprit is Assembly-CSharp.csproj file, which has line about using latest C# version available:

<LangVersion>latest</LangVersion>

I suspect this should be fixed from Unity's side? To force specify C# version which Unity supports and uses right now.

To fix this - manually change version to 7.0 inside Assembly-CSharp.csproj file, like this:

<LangVersion>7.0</LangVersion>

 

Didn't anyone else experience this?

I am constantly suffer from errors I don't see in editor and some not even in Unity (syntax warnings), due to language versions mismatch.

Example: I had Object not set to instance error due to lack of short list initialization syntax:

List<Item> items = {
item,
item
};

I spent whole day catching this bug before I thought - hey.... Maybe the syntax doesn't work?...