anchor.diff:  REM Be sure to place the installed binary directory on your PATH.
   svn checkout https://svn.r-project.org/R/trunk/
   cd trunk
  -
  -REM Put Rtools on the path.
  -SET "PATH=C:\Rtools\bin;%PATH%"
   
   REM Copy in the 'extras' for a 64bit build. This includes tcltk
   REM plus some other libraries. Note that the R64 directory should
  
positive.code: REM - BEGIN CONFIGURATION VARIABLES -
  REM ---------------------------------
  
  SET "CRAN=http://cran.r-project.org"
  SET "RTOOLS_VERSION=33"
  SET "ROOT_DIR=C:\R-src"
  SET "R_HOME=C:\R-src\trunk"
  SET "RTOOLS_BIN_DIR=C:\Rtools\bin"
  SET "TMPDIR=C:\tmp"
  
  REM -------------------------------
  REM - END CONFIGURATION VARIABLES -
  REM -------------------------------
  
  REM Set the current directory.
  if not exist "%ROOT_DIR%" (
  
negative.code: REM URI to RTools.exe
  SET "RTOOLS_URL=%CRAN%/bin/windows/Rtools/Rtools%RTOOLS_VERSION%.exe"
  
  REM URI to updated toolchains.
  REM TODO Remove this once Rtools stabilized.
  SET "TOOLCHAIN_BASE=http://www.stats.uwo.ca/faculty/murdoch/temp"
  SET "TOOLCHAIN_32BIT=%TOOLCHAIN_BASE%/mingw32mingw32_gcc-4.9.2.toolchain.tar.gz"
  SET "TOOLCHAIN_64BIT=%TOOLCHAIN_BASE%/mingw32mingw64_gcc-4.9.2.toolchain.tar.gz"
  
  REM Download Rtools, and the updated toolchains.
  REM TODO: Downloading the upgraded toolchains will not be necessary
  REM once RTOOLS has been fully stabilized.
  wget -c %RTOOLS_URL%
  wget -c %TOOLCHAIN_32BIT%
  wget -c %TOOLCHAIN_64BIT%
  
  REM Install Rtools.
  SET "RTOOLS_INSTALLER=.\Rtools%RTOOLS_VERSION%.exe"
  "%RTOOLS_INSTALLER%" /VERYSILENT
  
  REM Put Rtools on the path.
  SET "PATH=%RTOOLS_BIN_DIR%;%PATH%"
  
  REM Overwrite the toolchain paths with our own.
  rmdir /S /Q %RTOOLS_DIR%\gcc492_32
  rmdir /S /Q %RTOOLS_DIR%\gcc492_64
  
  REM Untar the downloaded toolchains and move them.
  tar -zxvf mingw32mingw32_gcc-4.9.2.toolchain.tar.gz
  move mingw32 %RTOOLS_DIR%\gcc492_32
  
  tar -zxvf mingw32mingw64_gcc-4.9.2.toolchain.tar.gz
  move mingw64 %RTOOLS_DIR%\gcc492_64
  
  REM Download the R sources. Get the latest R-devel sources using SVN.
  REM
  