.NET Core project.json supports NuGet importing (a.k.a. lying according to this SO answer). It is impossible to include a mscorlib based library due to an import statement.
{
"version": "1.0.0-*",
"dependencies": {
"Microsoft.AspNet.Identity.EntityFramework": "2.2.1",
"NETStandard.Library": "1.6.0"
},
"frameworks": {
"netstandard1.6": {
"imports": [
"net461"
]
}
}
}
Imports only work with portable class libraries (which are System.Runtime based) or deprecated target framework monikers which are also System.Runtime based (e.g. dotnet or dnxcore)