anchor.diff:  
   
   let pfx = "code-sign.pfx"
  +let mutable isUnsignedAllowed = true
  +Target "EnsurePackageSigned" (fun _ -> isUnsignedAllowed <- false)
   
   Target "SignAssemblies" (fun _ ->
       if not <| fileExists pfx then
  -        failwithf "%s not found, can't sign assemblies" pfx
  +        if isUnsignedAllowed then ()
  +        else failwithf "%s not found, can't sign assemblies" pfx
       else
   
       let filesToSign = 
  
positive.code: "ReleaseDocs"
    ==> "Release"
  
  "DotnetRestoreTools"
    ==> "MergeDotnetCoreIntoNuget"
  
  
negative.code:     |> Async.RunSynchronously
  )
  
  
  Target "Release" DoNothing
  Target "BuildPackage" DoNothing
  Target "BuildCore" DoNothing
  