Different upstream tools have different language configuration requirements: - dotnet CLI sets `DOTNET_CLI_UI_LANGUAGE` and `VSLANG` (https://github.com/Microsoft/msbuild/issues/1596#issuecomment-409362785 https://github.com/dotnet/cli/issues/9722#issuecomment-409358296) - Visual Studio has a [fallback mechanism guideline](https://microsoft.sharepoint.com/teams/DD_Tenets/World%20Ready/Localizability/SitePages/Language%20Pack%20-%20Extended%20Guidance.aspx). In order: - `VSLANG` environmnent variable - `/lcid` command line switch - call `GetConsoleFallbackUICulture` (**we only do this currently**) Related info: https://github.com/dotnet/cli/issues/4988#issuecomment-266836559