code: def source_cmd(args, stdin=None):
      
      args = list(args)
      fpath = locate_binary(args[0])
      args[0] = fpath if fpath else args[0]
      if not os.path.isfile(args[0]):
          raise RuntimeError("Command not found: %s" % args[0])
      prevcmd = 'call '
      prevcmd += ' '.join([argvquote(arg, force=True) for arg in args])
      prevcmd = escape_windows_cmd_string(prevcmd)
      args.append('--prevcmd={}'.format(prevcmd))
      args.insert(0, 'cmd')
      args.append('--interactive=0')
      args.append('--sourcer=call')
      args.append('--envcmd=set')
      args.append('--seterrpostcmd=if errorlevel 1 exit 1')
      args.append('--use-tmpfile=1')
      return source_foreign(args, stdin=stdin)
docs: Simple cmd.exe-specific wrapper around source-foreign.
  
      returns a dict to be used as a new environment