anchor.diff:  
   Target "SignAssemblies" (fun _ ->
       if not <| fileExists pfx then
  -        traceImportant (sprintf "%s not found, skipped signing assemblies" pfx)
  +        failwithf "%s not found, can't sign assemblies" pfx
       else
   
       let filesToSign = 
  
positive.code:     |> Async.RunSynchronously
  )
  
  Target "Release" (fun _ ->
      if not <| fileExists pfx then
          failwithf "%s not found - can't sign release." pfx
  )
  
  Target "BuildPackage" DoNothing
  Target "BuildCore" DoNothing
  // --------------------------------------------------------------------------------------
  
negative.code: 
  "All"
    ==> "MergePaketTool"
    =?> ("RunIntegrationTests", not <| hasBuildParam "SkipIntegrationTests")
    ==> "SignAssemblies"
    ==> "CalculateDownloadHash"
    =?> ("NuGet", not <| hasBuildParam "SkipNuGet")
    =?> ("MergeDotnetCoreIntoNuget", not <| hasBuildParam "DISABLE_NETCORE" && not <| hasBuildParam "SkipNuGet")
  