Question: I'm using VS 2019 16.9.0 Preview 1.0 and have a project with the following PropertyGroup

```
<PropertyGroup>
  <OutputType>Exe</OutputType>
  <TargetFramework>net5.0</TargetFramework>
  <LangVersion>latest</LangVersion>
  <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
  <EnableNETAnalyzers>true</EnableNETAnalyzers>
</PropertyGroup>

```

In my .editorconfig I created rules for fields to start with an underscore `_`. in Visual Studio I can see the error as `IDE1006`. However this does not cause the build to fail. From what I have read the setting `<EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>` should cause the build to fail. I tested this in Visual Studio and from the Command Line using `dotnet build`.

How can I have this error to cause a build failure?

Answer: 
You have to set `dotnet_diagnostic.IDE1006.severity = error` or `warning` to get it work. CLI only recognize this syntax.

See one of my related [answer](https://stackoverflow.com/questions/69486362/editorconfig-control-file-scoped-namespace-declaration/69902790#69902790) on similar topic.
Pass the /WarnAsError flag to dotnet build:

`dotnet build /WarnAsError`