def make_bad_fd():
file = open(TESTFN, "<STR_LIT:wb>")<EOL>try:<EOL><INDENT>return file.fileno()<EOL><DEDENT>finally:<EOL><INDENT>file.close()<EOL>unlink(TESTFN)<EOL><DEDENT>
Create an invalid file descriptor by opening and closing a file and return
its fd.