Added ability to invoke pdb on IPython crashes.

For now it has to be turned on manually in the code, will add a flag later.
But very useful for debugging apps that use/extend IPython itself and can
possibly crash it.

IPython/core/crashhandler.py

@@ -1,220 +1,228 b''
 # -*- coding: utf-8 -*-
 """sys.excepthook for IPython itself, leaves a detailed report on disk.
 
 
 Authors
 -------
 - Fernando Perez <[e-mail]>
 """
 
 #*****************************************************************************
 #       Copyright (C) 2008-2009 The IPython Development Team
 #       Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 #****************************************************************************
 # Required modules
 
 # From the standard library
 import os
 import sys
 from pprint import pformat
 
 # Our own
 from IPython.core import release
 from IPython.core import ultratb
 from IPython.external.Itpl import itpl
 
 #****************************************************************************
 class CrashHandler(object):
     """Customizable crash handlers for IPython-based systems.
 
     Instances of this class provide a __call__ method which can be used as a
     sys.excepthook, i.e., the __call__ signature is:
 
         def __call__(self,etype, evalue, etb)
 
     """
 
     def __init__(self,app, app_name, contact_name=None, contact_email=None, 
                  bug_tracker=None, crash_report_fname='CrashReport.txt', 
-                 show_crash_traceback=True):
+                 show_crash_traceback=True, call_pdb=False):
         """New crash handler.
 
         Inputs:
 
         - app: a running application instance, which will be queried at crash
         time for internal information.
 
         - app_name: a string containing the name of your application.
 
         - contact_name: a string with the name of the person to contact.
 
         - contact_email: a string with the email address of the contact.
 
         - bug_tracker: a string with the URL for your project's bug tracker.
 
         - crash_report_fname: a string with the filename for the crash report
         to be saved in.  These reports are left in the ipython user directory
         as determined by the running IPython instance.
 
         Optional inputs:
         
         - show_crash_traceback(True): if false, don't print the crash
         traceback on stderr, only generate the on-disk report
 
 
         Non-argument instance attributes:
 
         These instances contain some non-argument attributes which allow for 
         further customization of the crash handler's behavior.  Please see the
         source for further details.
         """
 
         # apply args into instance
         self.app = app
         self.app_name = app_name
         self.contact_name = contact_name
         self.contact_email = contact_email
         self.bug_tracker = bug_tracker
         self.crash_report_fname = crash_report_fname
         self.show_crash_traceback = show_crash_traceback
         self.section_sep = '\n\n'+'*'*75+'\n\n'
+        self.call_pdb = call_pdb
+        #self.call_pdb = True # dbg
         
         # Hardcoded defaults, which can be overridden either by subclasses or
         # at runtime for the instance.
 
         # Template for the user message.  Subclasses which completely override
         # this, or user apps, can modify it to suit their tastes.  It gets
         # expanded using itpl, so calls of the kind $self.foo are valid.
         self.user_message_template = """
 Oops, $self.app_name crashed. We do our best to make it stable, but...
 
 A crash report was automatically generated with the following information:
   - A verbatim copy of the crash traceback.
   - A copy of your input history during this session.
   - Data on your current $self.app_name configuration.
 
 It was left in the file named:
 \t'$self.crash_report_fname'
 If you can email this file to the developers, the information in it will help
 them in understanding and correcting the problem.
 
 You can mail it to: $self.contact_name at $self.contact_email
 with the subject '$self.app_name Crash Report'.
 
 If you want to do it now, the following command will work (under Unix):
 mail -s '$self.app_name Crash Report' $self.contact_email < $self.crash_report_fname
 
 To ensure accurate tracking of this issue, please file a report about it at:
 $self.bug_tracker
 """
 
     def __call__(self,etype, evalue, etb):
         """Handle an exception, call for compatible with sys.excepthook"""
 
         # Report tracebacks shouldn't use color in general (safer for users)
         color_scheme = 'NoColor'
 
         # Use this ONLY for developer debugging (keep commented out for release)
         #color_scheme = 'Linux'   # dbg
         
         try:
             rptdir = self.app.ipython_dir
         except:
             rptdir = os.getcwd()
         if not os.path.isdir(rptdir):
             rptdir = os.getcwd()
         report_name = os.path.join(rptdir,self.crash_report_fname)
         # write the report filename into the instance dict so it can get
         # properly expanded out in the user message template
         self.crash_report_fname = report_name
         TBhandler = ultratb.VerboseTB(color_scheme=color_scheme,
-                                      long_header=1)
-        traceback = TBhandler.text(etype,evalue,etb,context=31)
+                                      long_header=1,
+                                      call_pdb=self.call_pdb,
+                                      )
+        if self.call_pdb:
+            TBhandler(etype,evalue,etb)
+            return
+        else:
+            traceback = TBhandler.text(etype,evalue,etb,context=31)
 
         # print traceback to screen
         if self.show_crash_traceback:
             print >> sys.stderr, traceback
 
         # and generate a complete report on disk
         try:
             report = open(report_name,'w')
         except:
             print >> sys.stderr, 'Could not create crash report on disk.'
             return
 
         # Inform user on stderr of what happened
         msg = itpl('\n'+'*'*70+'\n'+self.user_message_template)
         print >> sys.stderr, msg
 
         # Construct report on disk
         report.write(self.make_report(traceback))
         report.close()
         raw_input("Hit <Enter> to quit this message (your terminal may close):")
 
     def make_report(self,traceback):
         """Return a string containing a crash report."""
         import platform
         
         sec_sep = self.section_sep
         
         report = []
         rpt_add = report.append
         
         rpt_add('*'*75+'\n\n'+'IPython post-mortem report\n\n')
         rpt_add('IPython version: %s \n' % release.version)
         rpt_add('BZR revision   : %s \n' % release.revision)
         rpt_add('Platform info  : os.name -> %s, sys.platform -> %s\n' %
                      (os.name,sys.platform) )
         rpt_add('               : %s\n' % platform.platform())
         rpt_add('Python info    : %s\n' % sys.version)	     
 
         try:
             config = pformat(self.app.config)
             rpt_add(sec_sep+'Current user configuration structure:\n\n')
             rpt_add(config)
         except:
             pass
         rpt_add(sec_sep+'Crash traceback:\n\n' + traceback)
 
         return ''.join(report)
 
 
 class IPythonCrashHandler(CrashHandler):
     """sys.excepthook for IPython itself, leaves a detailed report on disk."""
     
     def __init__(self, app, app_name='IPython'):
 
         # Set here which of the IPython authors should be listed as contact
         AUTHOR_CONTACT = 'Fernando'
         
         # Set argument defaults
         bug_tracker = 'https://bugs.launchpad.net/ipython/+filebug'
         contact_name,contact_email = release.authors[AUTHOR_CONTACT][:2]
         crash_report_fname = 'IPython_crash_report.txt'
         # Call parent constructor
         CrashHandler.__init__(self,app,app_name,contact_name,contact_email,
                               bug_tracker,crash_report_fname)
 
     def make_report(self,traceback):
         """Return a string containing a crash report."""
 
         sec_sep = self.section_sep
         # Start with parent report
         report = [super(IPythonCrashHandler, self).make_report(traceback)]
         # Add interactive-specific info we may have
         rpt_add = report.append
         try:
             rpt_add(sec_sep+"History of session input:")
             for line in self.app.shell.user_ns['_ih']:
                 rpt_add(line)
             rpt_add('\n*** Last line of input (may not be in above history):\n')
             rpt_add(self.app.shell._last_input_line+'\n')
         except:
             pass
 
         return ''.join(report)