Bugs item #1180193, was opened at 2005-04-10 15:10 Message generated for change (Comment added) made by zseil You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1180193&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Python Interpreter Core Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Armin Rigo (arigo) Assigned to: Nobody/Anonymous (nobody) Summary: broken pyc files Initial Comment: In a number of situations, the .pyc files can become "corrupted" in a subtle way: the co_filename attribute of the code objects it contains become wrong. This can occur if we move or rename directories, or if we access the same set of files from two different locations (e.g. over NFS). This corruption doesn't prevent the .pyc files from working, but the interpreter looses the reference to the source file. It causes trouble in tracebacks, in the inspect module, etc. A simple fix would be to use the following logic when importing a .py file: if there is a corresponding .pyc file, in addition to checking the timestamp, check the co_filename attribute of the loaded object. If it doesn't point to the original .py file, discard the code object and ignore the .pyc file. Alternatively, we could force all co_filenames to point to the .py file when loading the .pyc file. I'll write a patch for whichever alternative seems better. ---------------------------------------------------------------------- >Comment By: Ziga Seilnacht (zseil) Date: 2007-04-24 12:01 Message: Logged In: YES user_id=1326842 Originator: NO Here is a patch that implements arigo's last suggestion. File Added: update_co_filename.diff ---------------------------------------------------------------------- Comment By: Ziga Seilnacht (zseil) Date: 2007-04-03 15:46 Message: Logged In: YES user_id=1326842 Originator: NO Wouldn't your first solution be simpler? Changing all co_filenames would require either changing various marhal.c functions, or traversing the code object returned by import.c/read_compiled_module(). Discarding the compiled code when the file names don't match would be simpler and only require minor changes in import.c/load_source_module(). ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2007-04-03 13:31 Message: Logged In: YES user_id=4771 Originator: YES If you ask me, I think that when the importing system finds both a .py and a .pyc for a module, then it should ignore all co_filename and replace them with the real path of the .py file. I can't see any point of not doing so. There are many other quirks caused by .pyc files accidentally remaining around, but we cannot fix them all as long as the .pyc files are at the same time a cache for performance reason and a redistributable program format (e.g. if "rm x.py" or "svn up" deletes a .py file, then the module is still importable via the .pyc left behind, a great way to oversee the fact that imports elsewhere in the project need to be updated). ---------------------------------------------------------------------- Comment By: Ziga Seilnacht (zseil) Date: 2007-04-03 09:16 Message: Logged In: YES user_id=1326842 Originator: NO This problem is reported quite often in the tracker, although it shows up in different places: http://www.python.org/sf/1666807 http://www.python.org/sf/1051638 I closed those bugs as duplicates of this one. The logging package is also affected: http://www.python.org/sf/1669498 http://www.python.org/sf/1633605 http://www.python.org/sf/1616422 ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2007-03-28 15:40 Message: Logged In: YES user_id=4771 Originator: YES What I called "corruption" is the situation where both the .py and the .pyc files are present, but the filename stored in the .pyc co_filenames is no longer the valid absolute path of the corresponding .py file, for any reason (renaming, NFS views, etc.). This situation causes the tracebacks and the inspect module to fail to locate the .py file, which I consider a bug. ---------------------------------------------------------------------- Comment By: Martin v. Löwis (loewis) Date: 2007-03-28 14:01 Message: Logged In: YES user_id=21627 Originator: NO I fail to see the corruption. It is quite desirable and normal to only ship pyc files - that the file name they refer to is actually present is not a requirement at all. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1180193&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
