anchor.diff:  
       // Build and minify REPL
       Yarn.install replDir
  -    Npm.script replDir "build" []
  -    Npm.script replDir "minify" []
  +    Yarn.run replDir "build" ""
  +    Yarn.run replDir "minify" ""
   
       // Copy generated files to `../fable-compiler.github.io/public/repl/build`
  -    let targetDir =  __SOURCE_DIRECTORY__ </> "../fable-compiler.github.io/public/repl"
  +    let targetDir =  CWD </> "../fable-compiler.github.io/public/repl"
       if Directory.Exists(targetDir) then
           let targetDir = targetDir </> "build"
           // fable-core
  -        [sprintf "--project %s -m amd --outDir %s" coreJsSrcDir (targetDir </> "fable-core")]
  -        |> Npm.script __SOURCE_DIRECTORY__ "tsc"
  +        sprintf "--project %s -m amd --outDir %s" coreJsSrcDir (targetDir </> "fable-core")
  +        |> Yarn.run CWD "tsc"
           // REPL bundle
           printfn "Copy REPL JS files to %s" targetDir
           for file in Directory.GetFiles(replDir </> "repl", "*.js") do
  
positive.code: 
  let dotnetcliVersion = "2.0.2"
  let mutable dotnetExePath = environVarOrDefault "DOTNET" "dotnet"
  let dotnetSDKPath = FullName "./dotnetsdk"
  let localDotnetExePath = dotnetSDKPath </> (if isWindows then "dotnet.exe" else "dotnet")
  
  let cliBuildDir = "build/fable"
  let coreBuildDir = "build/fable-core"
  let coreSrcDir = "src/dotnet/Fable.Core"
  
negative.code: #r "packages/build/FAKE/tools/FakeLib.dll"
  #load "paket-files/build/fsharp/FAKE/modules/Octokit/Octokit.fsx"
  #load "paket-files/build/fable-compiler/fake-helpers/Fable.FakeHelpers.fs"
  
  open System
  open System.IO
  open System.Text.RegularExpressions
  open Fake
  open Fake.Git
  open Octokit
  open Fable.FakeHelpers
  
  #if MONO
  // prevent incorrect output encoding (e.g. https://github.com/fsharp/FAKE/issues/1196)
  System.Console.OutputEncoding <- System.Text.Encoding.UTF8
  #endif
  
  module Yarn =
      open YarnHelper
  
      let install workingDir =
          Yarn (fun p ->
              { p with
                  Command = YarnCommand.Install InstallArgs.Standard
                  WorkingDirectory = workingDir
              })
  
      let run workingDir script args =
          Yarn (fun p ->
              { p with
                  Command = YarnCommand.Custom ("run " + script + " " + args)
                  WorkingDirectory = workingDir
              })
  
  // Project info
  let project = "Fable"
  