anchor.diff:  echo Compiling MongoDB driver library ...
   devenv libmongoc.sln /project mongoc_static /rebuild Release >nul 2>&1
   if ERRORLEVEL 1 (
  +  :: Shows error
  +  devenv libmongoc.sln /project mongoc_static /build Release
  +  echo;
     echo Build failed.
     echo MongoDB driver not available.
     exit /b
  
positive.code: ::
  :: Generates tfenv.bat
  ::
  for %%I in (qmake.exe) do if exist %%~$path:I set QMAKE=%%~$path:I
  for %%I in (cmake.exe) do if exist %%~$path:I set CMAKE=%%~$path:I
  for %%I in (cl.exe)    do if exist %%~$path:I set MSCOMPILER=%%~$path:I
  for %%I in (g++.exe)   do if exist %%~$path:I set GNUCOMPILER=%%~$path:I
  
  if "%QMAKE%" == "" (
    echo Qt environment not found
  
negative.code: :break
  
  :: vcvarsall.bat setup
  set MAKE=nmake
  if /i "%Platform%" == "x64" (
    set VCVARSOPT=amd64
    set BUILDTARGET=x64
    set ENVSTR=Environment to build for 64-bit executable  MSVC / Qt
  ) else (
    set VCVARSOPT=x86
    set BUILDTARGET=win32
    set ENVSTR=Environment to build for 32-bit executable  MSVC / Qt
  )
  
  echo %QT_INSTALL_PREFIX% | find "msvc2015" >NUL
  if not ERRORLEVEL 1 (
    if /i "%Platform%" == "x64" (
      set CMAKEOPT=Visual Studio 14 2015 Win64
    ) else (
      set CMAKEOPT=Visual Studio 14 2015
    )
  ) else (
     if /i "%Platform%" == "x64" (
      set CMAKEOPT=Visual Studio 15 2017 Win64
    ) else (
      set CMAKEOPT=Visual Studio 15 2017
    )
  )
  
  SET /P X="%ENVSTR%"<NUL
  qtpaths.exe --qt-version
  
  for %%I in (qtenv2.bat) do if exist %%~$path:I set QTENV=%%~$path:I
  set TFENV=tfenv.bat
  