anchor.diff:  
       // tools
       let xunitRunnerExe = lazy ((getNugetPackage "xunit.runner.console" "2.1.0") @@ "tools" @@ "xunit.console.exe")
  -    let nunitRunnerExe = lazy ((getNugetPackage "NUnit.Runners" "3.2.0") @@ "tools" @@ "nunit3-console.exe")
  +    let nunitRunnerExe = lazy ((getNugetPackage "NUnit.ConsoleRunner" "3.2.0") @@ "tools" @@ "nunit3-console.exe")
       let openCoverExe = lazy ((getNugetPackage "OpenCover" "4.6.519") @@ "tools" @@ "OpenCover.Console.exe")
       let coverallsExe = lazy ((getNugetPackage "coveralls.io" "1.3.4") @@ "tools" @@ "coveralls.net.exe")
       let coverityExe = lazy ("C:/CoverityScan/win64/bin/cov-build.exe") // TODO: install coverity scan if absent
  
positive.code:         |> Seq.map (fun i -> let _, p = i in p)
          |> Seq.where (fun p -> p.Contains ".Tests.")
          |> Seq.map (fun p -> Path.GetDirectoryName(p) @@ "bin" @@ solution.Configuration @@ Path.GetFileNameWithoutExtension(p) + ".dll")
          |> List.ofSeq 
  
      // test and publish result to appveyor
      let testSolution solution = 
  
negative.code:             let ppath = Path.GetDirectoryName(List.head testDlls)
              let testRunnerExePath, testArgs = 
                  if File.Exists(ppath @@ "xunit.core.dll") then (xunitRunnerExe.Force(), "-noshadow")
                  elif File.Exists(ppath @@ "nunit.framework.dll") then (nunitRunnerExe.Force(), "")
                  else failwithf "Failed to test project because test framework cannot be determined."
              testDlls
              |> String.concat " "
  