msbuild /t:pack fails when building a stable versioned package that depends on an unstable one, even though that unstable one is a DevelopmentDependency:

1. Create .NET Core console app
2. Add this package reference

   <PackageReference Include="Nerdbank.GitVersioning" Version="1.5.28-rc" developmentDependency="true" />`

3. Pack the project with msbuild /t:pack

Build fails with a crashed MSBuild task with this message:

C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Sdks\NuGet.Build.Tasks.Pack\buildCrossTargeting\NuGet.Build.Tasks.Pack.targets(73,5): error MSB4018:
The "PackTask" task failed unexpectedly.\r [C:\Users\andre\OneDrive\Documents\Visual Studio 2017\Projects\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj]
C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Sdks\NuGet.Build.Tasks.Pack\buildCrossTargeting\NuGet.Build.Tasks.Pack.targets(73,5): error MSB4018: System.IO.InvalidDataException: A stable release of a package should not have a prerelease dependency. Either modify the version spec of dependency "Nerdbank.GitVersionin
g [1.5.61-ga5f362ccc1, )" or update the version field in the nuspec.\r [C:\Users\andre\OneDrive\Documents\Visual Studio 2017\Projects\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj]

In fact I shouldn't even have to specify DevelopmentDependency="true" in my reference because the nuspec of the referenced package itself has that property set.