anchor.diff:  @if %abi%==x64 set minabi=64
   @set vsenv=%ProgramFiles%
   @if NOT "%ProgramW6432%"=="" set vsenv=%vsenv% (x86)
  -@set vsenv15=%vsenv%\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvars%minabi%.bat
  -@set vsenv14=%VS140COMNTOOLS%..\..\VC\bin\vcvars%minabi%.bat
  +@set vsenv=%vsenv%\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvars%minabi%.bat
  +@set toolchain=Visual Studio 15 2017
  +@if NOT EXIST "%vsenv%" (
  +@set vsenv=%VS140COMNTOOLS%..\..\VC\bin\vcvars%minabi%.bat
  +@set toolchain=Visual Studio 14
  +)
   @set gcc=%mesa%mingw-w64-%abi%\mingw%minabi%\bin
   @set vsenvloaded=0
   @set dxtnbuilt=0
  
positive.code: @echo.
  @md cmake-%abi%
  @cd cmake-%abi%
  @if EXIST "%vsenv15%" (
  @set vsenvloaded=%vsenvloaded%15
  @set toolchain=Visual Studio 15 2017
  @call "%vsenv15%"
  )
  @if NOT EXIST "%vsenv15%" (
  @set vsenvloaded=%vsenvloaded%14
  @set toolchain=Visual Studio 14
  @call "%vsenv14%"
  )
  @if %abi%==x64 @set toolchain=%toolchain% Win64
  @set PATH=%mesa%cmake\%abi%\bin\;%PATH%
  @echo.
  
negative.code: @pip freeze > requirements.txt
  @pip install -r requirements.txt --upgrade
  @del requirements.txt
  @echo.
  @if %vsenvloaded%==0 (
  @call "%vsenv%"
  @echo.
  )
  
  :build_mesa_exec
  @python "%mesa%Python\%abi%\Scripts\scons.py" build=release platform=windows machine=%longabi% toolchain=%mesatoolchain% swr=%buildswr% libgl-gdi
  