CoApp Does Not Allow ASCII-Extended Characters During Package Creation

[felsokning]

Problem:
CoApp does not allow ASCII-Extended characters, even though the extended character set is supported by MSBuild and many other compilers (gcc, for example).

Reproduction:

1>------ Build started: Project: Felsökning.Utilities.Native.SwedishUtilities, Configuration: Debug Win32 ------
1>pch.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.vcxproj -> ..\Debug\Felsökning.Utilities.Native.SwedishUtilities.lib

1>------ Build started: Project: Felsökning.Utilities.Native.SwedishUtilities, Configuration: Debug x64 ------
1>pch.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.vcxproj -> ..\x64\Debug\Felsökning.Utilities.Native.SwedishUtilities.lib

1>------ Build started: Project: Felsökning.Utilities.Native.SwedishUtilities, Configuration: Release Win32 ------
1>pch.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.vcxproj -> ..\Release\Felsökning.Utilities.Native.SwedishUtilities.lib

1>------ Build started: Project: Felsökning.Utilities.Native.SwedishUtilities, Configuration: Release x64 ------
1>pch.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.cpp
1>Felsokning.Utilities.Native.SwedishUtilities.vcxproj -> ..\x64\Release\Felsökning.Utilities.Native.SwedishUtilities.lib

Write-NuGetPackage .\nuget.autopkg
 >Attempting to build package from 'Fels?kning.Utilities.Native.SwedishUtilities.nuspec'.
 >The package ID 'Fels?kning.Utilities.Native.SwedishUtilities' contains invalid characters. Examples of valid package IDs include 'MyPackage' and 'MyPackage.Sample'.

Expected Outcome:
CoApp builds the package for publish, sans any issue.

Actual Outcome:
The package isn't built and renaming of everything in the project has to occur, to accommodate normal ASCII characters.

Example:
I have several managed libraries on NuGet with the extended character-set, already; so, from a supportability perspective, ASCII-Extended isn't much of an issue, at all.

Felsökning.Utilities.SvenskaUtilities