bug#5653: 23.1; pdbtrack isn't parsing valid pdb output or creating an interactive debugging buffer (python.el)

[Jeremy Whitlock]

Python debugging with gud-pdb appears to be broken.  There are actually two 
problems:


1) While debugging Python code in emacs I kept seeing "Traceback cue not found" 
errors popping up in the minibuffer.  After a good bit of googling, I found 
this:

https://bugs.launchpad.net/python-mode/+bug/505295

Once I applied this patch, those errors went away.  Here is the patch:

--- a/python.el 2010-02-26 13:47:13.000000000 -0700
+++ b/python.el 2010-02-26 13:47:38.000000000 -0700
@@ -575,7 +575,7 @@
(defvar python-pdbtrack-is-tracking-p nil)

(defconst python-pdbtrack-stack-entry-regexp
-  "^> \\(.*\\)(\\([0-9]+\\))\\([?a-zA-Z0-9_]+\\)()"
+  "^> \\(.*\\)(\\([0-9]+\\))\\([?a-zA-Z0-9_<>]+\\)()"
   "Regular expression pdbtrack uses to find a stack trace entry.")

(defconst python-pdbtrack-input-prompt "\n[(<]*[Pp]db[>)]+ "

2) Debugging Python in emacs doesn't work with "M-x pdb".  If I invoke pdb 
using "M-x pdb", I end up at a buffer that says:

Current directory is <pwd>

No matter what I do, the buffer never updates or creates an interactive pdb 
shell until I kill the debugging session by running to the end of the script or 
killing the debugger session.  It's at this point I see exactly what I would 
had expected to see in the first place, the pdb interactive session and its 
output.  The only way I can debug Python in emacs is to open a shell, invoke 
"python -m pdb <file>".  The good news is python.el has support to 
automatically link the shell's pdb output to an editor pointing to the file 
being debugged.

In the end, with the patch applied, I can debug by manually invoking pdb from a 
shell buffer (M-x shell) but even with that patch applied, pdb (M-x pdb) 
support fails to work as described earlier.  I think issue #1 can be fixed with 
the inline patch, as it does make it so you can debug Python in emacs where you 
cannot without the patch being applied.  Please let me know if there is more 
information I can provide.

Environment Information
---------------------------------
Emacs: 23.1.1 (http://emacsformacosx.com/)
OS: Mac OS X 10.6.2 (Snow Leopard)
Python: 2.6.1

In GNU Emacs 23.1.1 (i386-apple-darwin9.8.0, NS apple-appkit-949.54)
of 2009-08-16 on black.local
Windowing system distributor `Apple', version 10.3.1038
configured using `configure  '--with-ns''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: nil
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  show-paren-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e p o r t - e m a <tab> <return>

Recent messages:
Loading /Users/jwhitlock/.emacs.d/color-theme/themes/color-theme-example.el 
(source)...done
Loading /Users/jwhitlock/.emacs.d/color-theme/themes/color-theme-library.el 
(source)...done
Loading /Users/jwhitlock/.emacs.frameg...done
For information about GNU Emacs and the GNU system, type C-h C-a.

Jeremy Whitlock <jcscoobyrs@gmail.com>
http://www.thoughtspark.org