tool install cannot install on culture "en-US-POSIX" -- `dotnet tool install` cannot install on ubuntu 18.04

https://github.com/NuKeeperDotNet/NuKeeper/issues/433 https://github.com/dotnet/cli/issues/9974

on WSL ubuntu 18.04

Run dotnet tool install --global NuKeeper on WSL ubuntu 18.04. Get error The settings file in the tool's NuGet package is invalid: Settings file 'DotnetToolSettings.xml' was not found in the package. Tool 'nukeeper' failed to install. Please contact the tool author for assistance.

[wli3]

Minimal repro

private static void Main(string[] args)
        {
            CultureInfo.CurrentCulture = new CultureInfo("en-US-POSIX");
            Console.WriteLine("CurrentCulture is {0}.", CultureInfo.CurrentCulture.Name);
            Console.WriteLine(string.Compare("nukeeper", "NuKeeper", StringComparison.CurrentCultureIgnoreCase) == 0);
        }

[danmoseley]

cc @tarekgh