code: def exec_(argv):  # never returns
      
      # info('EXEC' + colorize(argv))  # TODO: debug logging by environment variable
  
      # in python3, sys.exitfunc has gone away, and atexit._run_exitfuncs seems to be the only pubic-ish interface
      #   https://hg.python.org/cpython/file/3.4/Modules/atexitmodule.c#l289
      import atexit
      atexit._run_exitfuncs()
  
      from os import execv
      execv(argv[0], argv)
docs: Wrapper to os.execv which shows the command and runs any atexit handlers (for coverage's sake).
      Like os.execv, this function never returns.