[Unity] generated csproj does not contain nullable enable when enabled via csc.rsp

[BarionLP]

Describe the Issue

in unity can compile with nullable warnings enabled via the compiler response file (csc.rsp) but the generated csproj does not contain <Nullable>enable</Nullable> resulting in the nullable warnings only being displayed in unity.

Right now this is a very niche thing to do but I assume it will become more relevant with unity moving to core clr

Steps To Reproduce

1. add -nullable:enable to a projects csc.rsp file
2. nullable warnings will show up in unity but not in vs code, vs code will show warnings when using nullable related features

Expected Behavior

nullable warnings show up in vs code and vs code shows no warnings when using nullable related features

Environment Information

• Windows 11
• VS Code 1.109.4
• Unity 6000.3.7f1
• Unity Extension: 1.2.1

[sailro]

It is not related to the vscode extension but to the VS Editor Package in Unity.

Indeed we are not propagating this property when generating csproj files.

[sailro]

As a workaround until we add support for this, you can use an AssetPostProcessor to participate to the project generation, and add your custom attributes:

https://learn.microsoft.com/visualstudio/gamedev/unity/extensibility/customize-project-files-created-by-vstu