Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!goblin2!goblin.stu.neva.ru!newsfeed.xs4all.nl!newsfeed1.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'handler': 0.05; 'preferred.': 0.05; '"""': 0.07; 'debug': 0.07; 'debugging': 0.07; 'method.': 0.07; 'skip:" 60': 0.07; 'skip:u 30': 0.07; '__init__': 0.09; 'function,': 0.09; 'python': 0.11; 'thread': 0.14; '(pdb)': 0.16; '126': 0.16; '586': 0.16; '590': 0.16; '610': 0.16; '853': 0.16; 'breakpoint': 0.16; 'called.': 0.16; 'fingerprint:': 0.16; 'fruit': 0.16; 'gpg': 0.16; 'intended.': 0.16; 'pairs': 0.16; 'pairs:': 0.16; 'skip:/ 60': 0.16; 'skip:/ 70': 0.16; 'string:': 0.16; 'trying': 0.19; 'stack': 0.19; 'id:': 0.23; 'this?': 0.23; 'header:User-Agent:1': 0.23; 'module,': 0.24; 'unicode': 0.24; 'skip:" 30': 0.26; 'this:': 0.26; 'skip:" 20': 0.27; 'tried': 0.27; 'point': 0.28; 'rest': 0.29; 'on,': 0.29; 'evaluation': 0.30; "i'm": 0.30; 'gives': 0.31; 'code': 0.31; 'getting': 0.31; 'anyone': 0.31; 'file': 0.32; 'regular': 0.32; 'run': 0.32; 'entirely': 0.33; 'skip:_ 10': 0.34; 'could': 0.34; 'problem.': 0.35; 'skip:s 30': 0.35; 'but': 0.35; 'there': 0.35; 'really': 0.36; 'executing': 0.36; 'interaction': 0.36; 'skip:" 50': 0.36; 'method': 0.36; 'possible': 0.36; 'subject:?': 0.36; 'should': 0.36; 'handle': 0.38; 'to:addr:python-list': 0.38; 'list,': 0.38; 'does': 0.39; 'to:addr:python.org': 0.39; 'skip:p 20': 0.39; 'received:org': 0.40; 'called': 0.40; 'how': 0.40; 'skip:u 10': 0.60; 'skip:* 10': 0.61; 'reach': 0.63; 'close': 0.67; '666': 0.84; '_bootstrap': 0.84; 'characters,': 0.84; 'flies': 0.84; 'self.run()': 0.84; 'trickery': 0.84; '169': 0.91; 'encrypted': 0.91 From: Nikolaus Rath To: python-list@python.org Subject: Corrputed stacktrace? Mail-Copies-To: never Mail-Followup-To: python-list@python.org Date: Tue, 03 Jun 2014 19:20:49 -0700 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 128 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1401848454 news.xs4all.nl 2829 [2001:888:2000:d::a6]:51217 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:72575 Hello, I'm trying to debug a problem. As far as I can tell, one of my methods is called at a point where it really should not be called. When setting a breakpoint in the function, I'm getting this: > /home/nikratio/in-progress/s3ql/src/s3ql/backends/s3c.py(693)close() -> if not self.md5_checked: (Pdb) bt /usr/lib/python3.3/threading.py(878)_bootstrap() -> self._bootstrap_inner() /usr/lib/python3.3/threading.py(901)_bootstrap_inner() -> self.run() /usr/lib/python3.3/threading.py(858)run() -> self._target(*self._args, **self._kwargs) /usr/lib/python3.3/socketserver.py(610)process_request_thread() -> self.finish_request(request, client_address) /usr/lib/python3.3/socketserver.py(345)finish_request() -> self.RequestHandlerClass(request, client_address, self) /usr/lib/python3.3/socketserver.py(666)__init__() -> self.handle() /home/nikratio/in-progress/s3ql/tests/mock_server.py(77)handle() -> return super().handle() /usr/lib/python3.3/http/server.py(402)handle() -> self.handle_one_request() /usr/lib/python3.3/http/server.py(388)handle_one_request() -> method() /home/nikratio/in-progress/s3ql/tests/mock_server.py(169)do_GET() -> q =3D parse_url(self.path) /home/nikratio/in-progress/s3ql/tests/mock_server.py(52)parse_url() -> p.params =3D urllib.parse.parse_qs(q.query) /usr/lib/python3.3/urllib/parse.py(553)parse_qs() -> encoding=3Dencoding, errors=3Derrors) /usr/lib/python3.3/urllib/parse.py(585)parse_qsl() -> pairs =3D [s2 for s1 in qs.split('&') for s2 in s1.split(';')] /usr/lib/python3.3/urllib/parse.py(585)() -> pairs =3D [s2 for s1 in qs.split('&') for s2 in s1.split(';')] /home/nikratio/in-progress/s3ql/src/s3ql/backends/common.py(853)close() -> self.fh.close() > /home/nikratio/in-progress/s3ql/src/s3ql/backends/s3c.py(693)close() -> if not self.md5_checked: To me this does not make any sense. Firstly, the thread that is (apparently) calling close should never ever reach code in common.py. This thread is executing a socketserver handler that is entirely contained in mock_server.py and only communicates with the rest of the program via tcp. Secondly, the backtrace does not make sense. How can evaluation of=20 pairs =3D [s2 for s1 in qs.split('&') for s2 in s1.split(';')] in urllib/parse.py() result in a method call in backends/common.py? There is no trickery going on, qs is a regular string: (Pdb) up (Pdb) up (Pdb) up (Pdb) l 580 into Unicode characters, as accepted by the bytes.decode() me= thod. 581=20=20=09 582 Returns a list, as G-d intended. 583 """ 584 qs, _coerce_result =3D _coerce_args(qs) 585 -> pairs =3D [s2 for s1 in qs.split('&') for s2 in s1.split(';')] 586 r =3D [] 587 for name_value in pairs: 588 if not name_value and not strict_parsing: 589 continue 590 nv =3D name_value.split('=3D', 1) (Pdb) whatis qs (Pdb) p qs '' (Pdb) I have also tried to get a backtrace with the faulthandler module, but it gives the same result: Thread 0x00007f7dafdb4700: File "/usr/lib/python3.3/cmd.py", line 126 in cmdloop File "/usr/lib/python3.3/pdb.py", line 318 in _cmdloop File "/usr/lib/python3.3/pdb.py", line 345 in interaction File "/usr/lib/python3.3/pdb.py", line 266 in user_line File "/usr/lib/python3.3/bdb.py", line 65 in dispatch_line File "/usr/lib/python3.3/bdb.py", line 47 in trace_dispatch File "/home/nikratio/in-progress/s3ql/src/s3ql/backends/s3c.py", line 693= in clos File "/home/nikratio/in-progress/s3ql/src/s3ql/backends/common.py", line = 853 in c File "/usr/lib/python3.3/urllib/parse.py", line 585 in File "/usr/lib/python3.3/urllib/parse.py", line 585 in parse_qsl File "/usr/lib/python3.3/urllib/parse.py", line 553 in parse_qs File "/home/nikratio/in-progress/s3ql/tests/mock_server.py", line 52 in p= arse_url File "/home/nikratio/in-progress/s3ql/tests/mock_server.py", line 169 in = do_GET File "/usr/lib/python3.3/http/server.py", line 388 in handle_one_request File "/usr/lib/python3.3/http/server.py", line 402 in handle File "/home/nikratio/in-progress/s3ql/tests/mock_server.py", line 77 in h= andle File "/usr/lib/python3.3/socketserver.py", line 666 in __init__ File "/usr/lib/python3.3/socketserver.py", line 345 in finish_request File "/usr/lib/python3.3/socketserver.py", line 610 in process_request_th= read File "/usr/lib/python3.3/threading.py", line 858 in run File "/usr/lib/python3.3/threading.py", line 901 in _bootstrap_inner File "/usr/lib/python3.3/threading.py", line 878 in _bootstrap Is it possible that the stack got somehow corrupted? Does anyone have a suggestion how I could go about debugging this? I am using Python 3.3. Best, -Nikolaus --=20 GPG encrypted emails preferred. Key id: 0xD113FCAC3C4E599F Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F =C2=BBTime flies like an arrow, fruit flies like a Banana.=C2= =AB