anchor.diff:  
   ECHO =========== %~f0 ===========
   
  +:: use 64 bit python if platform is 64 bit
  +IF /I "%PLATFORM%" == "x64" set PATH=C:\Python27-x64;%PATH%
  +:: put 7z on path (needed for unpacking mapnik sdk)
  +SET PATH=C:\Program Files\7-Zip;%PATH%
   
  -::use 64 bit python if platform is 64 bit
  -IF /I "%PLATFORM%" == "x64" set PATH=C:\Python27-x64;%PATH%
  -SET PATH=C:\Program Files\7-Zip;%PATH%
  -::add local node to path (since we install it below)
  -SET PATH=%CD%;%PATH%;
  -
  +:: TODO - dist/dev/ is intended for dev releases of mapnik
  +:: We ideally want to get in the habit of only using Mapnik official releases
  +:: which will be uploaded to dist/
   SET MAPNIK_SDK_URL=https://mapnik.s3.amazonaws.com/dist/dev/mapnik-win-sdk-v%MAPNIK_GIT%-%platform%-%msvs_toolset%.0.7z
   ECHO fetching mapnik sdk^: %MAPNIK_SDK_URL%
   IF EXIST mapnik-sdk.7z (ECHO already downloaded) ELSE (powershell Invoke-WebRequest "${env:MAPNIK_SDK_URL}" -OutFile mapnik-sdk.7z)
  
positive.code: IF DEFINED ProgramFiles(x86) IF EXIST "%ProgramFiles(x86)%\nodejs" ECHO copying to "%ProgramFiles(x86)%\nodejs\node.exe" && COPY /Y node.exe "%ProgramFiles(x86)%\nodejs\"
  IF %ERRORLEVEL% NEQ 0 GOTO ERROR
  
  
  ECHO clear out node-gyp header cache
  IF "%msvs_toolset%" == "14" IF EXIST %USERPROFILE%\.node-gyp rd /s /q %USERPROFILE%\.node-gyp
  
  ECHO activating VS command prompt
  
negative.code: powershell Invoke-WebRequest "${env:NODE_URL}" -OutFile node.exe
  IF %ERRORLEVEL% NEQ 0 GOTO ERROR
  
  :: we replace the existing node.exe with our own
  :: we do this in place so that the npm path logic
  :: is preserved. The alternative might be to put
  :: our custom node.exe on PATH from a custom location
  :: and then pass `--prefix` to npm - but this is untested
  ECHO deleting node.exe programfiles x64
  IF EXIST "%ProgramFiles%\nodejs" ^
      IF EXIST "%ProgramFiles%\nodejs\node.exe" ^
  