anchor.diff:  
   rem where perl > NUL 2>&1
   rem if ERRORLEVEL 1 call:setup_perl
  -rem if "%failure%" neq "0" goto:done_with_error
  -
  -rem where ninja > NUL 2>&1
  -rem if ERRORLEVEL 1 call:install_ninja
   rem if "%failure%" neq "0" goto:done_with_error
   
   call:dolink . build ..\webrtc-deps\build
  
positive.code: 
  :set_path
  
   setx PATH "%PATH%;%~1"
   set PATH=%PATH%;%~1
   echo "%~1 added to path"
  goto:eof
  
  
negative.code: )
  goto:eof
  
  
  :dolink
  if NOT EXIST %~1\nul call:failure -1 "%~1 does not exist!"
  