NuGet Error NU5018
Invalid assembly reference 'xunit.dll'. Ensure that a file named 'xunit.dll' exists in the lib directory.
Issue
The nuspec file used to create the NuGet pack operation contained references
that do not exist in the .\lib
folder in the project directory.
Solution
Please ensure that any referenced assemblies are placed inside .\lib
folder which is in the same folder as the nuspec file used to create the package.