anchor.diff:  @if EXIST build\windows-%longabi% set /p cleanbuild=Do you want to clean build (y/n):
   @if EXIST build\windows-%longabi% echo.
   @if /I "%cleanbuild%"=="y" RD /S /Q build\windows-%longabi%
  -@if %vsenvloaded%==0 (
  -@call %vsenv%
   @cd %mesa%mesa
   @echo.
  -)
   
   :build_mesa_exec
   @%sconscmd%
  
positive.code: @set vsenv=%vsenv14%
  @if %toolset%==15 set vsenv=%vsenv15%
  @set PATH=%mesa%flexbison\;%PATH%
  @TITLE Building Mesa3D %abi%
  
  :build_llvm
  
negative.code: @echo %toolset% > %mesa%toolset-%abi%.ini
  
  :prep_mesa
  @set PATH=%oldpath%
  @cd %mesa%
  @set mesapatched=0
  @set branch=none
  