anchor.diff:  REM Trampoline into xenia-build
   REM ============================================================================
   
  -python xenia-build %*
  +%PYTHON_EXE% xenia-build %*
   EXIT /b %ERRORLEVEL%
   
   
  
positive.code: 
  CALL :check_python
  IF %_RESULT% NEQ 0 (
    ECHO ERROR:
    ECHO Python 2.7 must be installed and on PATH:
    ECHO https://www.python.org/ftp/python/2.7.9/python-2.7.9.msi
    GOTO :exit_error
  
negative.code: 
  :check_python
  SETLOCAL
  SET FOUND_PYTHON_EXE=""
  1>NUL 2>NUL CMD /c where python2
  IF NOT ERRORLEVEL 1 (
    ECHO FOUND PYTHON 2
    SET FOUND_PYTHON_EXE=python2
  )
  IF %FOUND_PYTHON_EXE% EQU "" (
    1>NUL 2>NUL CMD /c where python
    IF NOT ERRORLEVEL 1 (
      SET FOUND_PYTHON_EXE=python
    )
  )
  IF %FOUND_PYTHON_EXE% EQU "" (
    ECHO ERROR: no Python executable found on PATH.
    ECHO Make sure you can run 'python' or 'python2' in a Command Prompt.
    ENDLOCAL & SET _RESULT=1
    GOTO :eof
  )
  CMD /C %FOUND_PYTHON_EXE% -c "import sys; sys.exit(1 if not sys.version_info[:2] == (2, 7) else 0)"
  IF %ERRORLEVEL% NEQ 0 (
    ECHO ERROR: Python version mismatch - not 2.7
    ENDLOCAL & SET _RESULT=1
    GOTO :eof
  )
  ENDLOCAL & (
    SET _RESULT=0
    SET PYTHON_EXE=%FOUND_PYTHON_EXE%
  )
  GOTO :eof
  