Log in |
Server side debugging of Zope[Zope] - debugging notes (zope/python/emacs/windows)Simon Michael [email protected]Tue, 5 Jan 1999 07:59:37 -0800 Here are some rough notes from my recent zope debugging efforts - I hope that others will find them useful, or post corrections/improvements. - Environment: I am using NT Emacs and the cygwin bash shell on windows 98. So my paths generally have forward slashes. - I wanted to step through the code of an external method which was not working. So I tried debugging it with ZPublisher/Test.py, described in the zope docs. The command line I'm using now is: $Z/bin/python -i $Z/lib/python/ZPublisher/Test.py -d $Z/lib/python/Main /files/find_results python with the '-i' flag is required to get the interactive prompt in an emacs shell window. Also it ensures that I know exactly which version of python is being used. $Z is the path to my zope installation. /files/find_results is the url path to a DTML Document which calls my external method. - I could not set a breakpoint on my external method, apparently due to limitations of the standard pdb class. So I tried stepping right through zope's execution to that point, but it became clear that I needed a higher-level tool with good source display. So I explored various incarnations & versions of debugging tools: pdb, pydb, emacs modes, ddd. Eventually, I: - downloaded the latest python, 1.5.2b1. The pdb/bdb/cmd classes in this version incorporate various enhancements, in particular you can set a breakpoint in any file which is in your sys.path, as follows: pdb> import sys pdb> sys.path.append('/tools/zope/Extensions') pdb> b ExtranetFind.py:19 - running zope with the latest python gave warnings about API versions. Things were not working well at the time so for paranoia I copied the new pdb/bdb/cmd classes into zope's lib/python1.5 and used that. Either version seems to work fine aside from the warnings. - I downloaded the latest NT Emacs, 20.3.3.1.1. This fixed some problems, and has an up-to-date gud.el with pdb support. - I made a change to .../emacs/lisp/gud.el to get "M-x pdb" to work on windows: (defvar gud-pdb-marker-regexp "^> \\([-a-zA-Z0-9_/.:\\]*\\|<string>\\)(\\([0-9]+\\))\\([a-zA-Z0-9_]*\\|\\?\\)( )\\(->[^\n]*\\)?\n") ;fix for windows/dos pathnames - SKWM - I downloaded the latest python-mode.el from www.python.org - I added this in my ~/.emacs to match Test.py's altered pdb prompt (cosmetic fix): (add-hook 'pdb-mode-hook '(lambda () (setq comint-prompt-regexp "^pdb> *"))) ; for zope debugging - These made for a more convenient debug prompt: (eval-after-load "comint" '(define-key comint-mode-map "\M-p" 'comint-previous-matching-input-from-input)) (eval-after-load "comint" '(define-key comint-mode-map "\M-n" 'comint-next-matching-input-from-input)) (eval-after-load "comint" '(define-key comint-mode-map "\C-a" 'comint-bol)) (setq comint-input-ring-size 100) - NOW, I can step through zope in emacs with full source fontifying, etc (get help on the "gud-mode" function for keybindings). Type "M-x pdb", and at the "Run pdb" prompt enter the Test.py command line above. - In this situation, you can use "python -u" instead of "python -i" to skip the python prompt at the end of a run. -Simon
[Zope] - debugging notes, part 2Simon Michael [email protected]Tue, 5 Jan 1999 07:59:45 -0800
Ok, so now I can debug zope in emacs, and set breakpoints where I want. Back to the earlier problem! Some breakpoints which I think should get hit, do not get hit. Eg, a breakpoint on my external method. I don't yet know why this happens. *TWO MORE MISC CHANGES: - So that I could run Test.py with the '-t' flag on windows, I changed instances of '/dev/null' to '/zopetest.tmp' - For quicker debugging, I made a change at ExternalMethod/ExternalMethod.py line 244, to reload external methods every time: # SKWM - always reload (todo: check debug flag) # try: f=self._v_f # except: f=self.getFunction() f=self.getFunction(1,1) *SWITCHED TO PDOCUMENTTEMPLATE - I tried again to step through zope's publishing process and into my method.. still haven't quite managed it. - I thought, "well it goes through c code at some point (cDocumentTemplate) and maybe that's confusing the debugger". Not to mention me. So, in order to try pDocumentTemplate, I: - renamed lib/python/DocumentTemplate/cDocumentTemplate.pyd (to hide it); - changed DT_Util.py: #SKWM #except: from pDocumentTemplate import InstanceDict, TemplateDict, render_blocks except: from pDocumentTemplate import InstanceDict, TemplateDict, render_blocks class cDocument: pass - made a fix, or at least a change, in pDocumentTemplate.py, line 159 (allowed me to manage Documents again) : #SKWM r=str(inst) r=str(inst) - And now, zope appears to run fine using the pDocumentTemplate and I can step through it as far as I want. As before, some breakpoints which I would expect to get hit, don't. - With one exception - running with pDocumentTemplate appears to break access control. Same with BOBO_DEBUG_MODE=1. On with the battle! Advice welcome! -Simon
Hacking on through the zope jungle <chop> <bash> <ouch> Avoiding a fatal squeeze from certain large snakes <oof> I wonder if there's an easier trail around here somewhere. Here are some more brief notes, on the theory that someone may benefit.. or shoot me before I catch jungle madness.. - PYTHON SETTINGS I said that "python -u ..." also works when doing "M-x pdb" in emacs. Not true, stick with "python -i ..." to avoid problems. Added a whole bunch of zope dirs to the PYTHONPATH environment variable to allow imports. Works for python 1.5.2b1, but not for zope's python. - BREAKPOINTS AGAIN I wrote: > Ok, so now I can debug zope in emacs, and set breakpoints where I want. Spoke too soon. pdb's "b filename:lineno" doesn't work. Test.py's fbreak() function does work. Breakpoints can be configured in a .bobodb file. Eg: import ExternalMethod breakpoints = [ExternalMethod.ExternalMethod.__call__,] Doesn't matter if you use cDocumentTemplate or pDocumentTemplate. A breakpoint on the external method itself doesn't work. If I step in from the above, I can then set one that works. - DEBUGGING IN WEBSERVER MODE When running in Test.py's command-line mode, the #with statement which calls my method is initialized but never rendered (why ?). It works fine in normal webserver mode. I changed Test.py to fire up the whole zopeHTTPserver: # db.run('publish_module(file,environ=env,debug=1)',Publish.__dict__, {'file':file, 'env':env}) sys.argv = [] db.run('import serve',Publish.__dict__,{'file':file, 'env':env}) Run Test.py in debug mode with "M-x pdb", as before. It reads breakpoints from .bobodb (I hardcoded the path to make sure). Continue a few times and the webserver's running. Access the url with a browser to trigger the ExternalMethod breakpoint, step into your method and there you are (my holy grail). -Simon |