anchor.diff:  @if EXIST %vsenv15% set toolset=15
   @set ninja=n
   @set oldtoolset=n
  -@if EXIST "%mesa%ninja" set ninja=1
  +@if EXIST %mesa%ninja set ninja=1
   @if EXIST %vsenv15% set ninja=%ninja%2
   @if %ninja%==12 set /p oldtoolset=Build with MSVC 2015 backward compatibility toolset, alternative solution for LLVM 3.9.1 build with Visual Studio 2017 (y/n):
   @if %ninja%==12 echo.
  
positive.code: @set /p buildllvm=Begin LLVM build. Only needs to run once for each ABI and version. Proceed (y/n):
  @if /I NOT "%buildllvm%"=="y" GOTO build_dxtn
  @echo.
  @cd "%mesa%llvm"
  @if EXIST %abi% RD /S /Q %abi%
  @if EXIST cmake-%abi% RD /S /Q cmake-%abi%
  @md cmake-%abi%
  
negative.code: :build_with_mingw
  @set mingw=n
  @set mingwtest=0
  @if EXIST %gcc% set mingwtest=1
  @set msys2=%mesa%msys64\msys2_shell.cmd
  @if EXIST %msys2% set mingwtest=%mingwtest%2
  @if %mingwtest%==12 set /p mingw=Do you want to build with MinGW-W64 instead of Visual Studio (y=yes):
  @if %dxtnbuilt%==0 set PATH=%gcc%\;%PATH%
  @set mesatoolchain=crossmingw
  @copy %gcc%\%altabi%-w64-mingw32-gcc-ar.exe %gcc%\%altabi%-w64-mingw32-ar.exe
  @copy %gcc%\%altabi%-w64-mingw32-gcc-ranlib.exe %gcc%\%altabi%-w64-mingw32-ranlib.exe
  @call "%msys2%" -use-full-path
  pacman -Syu
  pacman -S python2
  