update-software-center crashed with order (MRO) for bases SafeConfigParser, object in __new__()

Status changed to 'Confirmed' because the bug affects multiple users.

I had the same problem after updating to 12.10, with software-center always crashing immediately. I fixed it by changing line 33 of /usr/share/software-center/softwarecenter/config.py from
class SoftwareCenterConfig(object, SafeConfigParser):
to
class SoftwareCenterConfig(SafeConfigParser):

Peter's fix works for me, until it's updated anyway

With Peter's fix I have the following:

➜ ~ software-center
2013-03-06 13:18:22,757 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2013-03-06 13:18:22,763 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2013-03-06 13:18:23,208 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2013-03-06 13:18:23,316 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None.
2013-03-06 13:18:23,328 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
2013-03-06 13:18:24,134 - softwarecenter.db.categories - WARNING - '/usr/share/desktop-directories/Utility.directory' has no name
2013-03-06 13:18:24,135 - softwarecenter.db.categories - WARNING - '/usr/share/desktop-directories/Utility-Accessibility.directory' has no name
2013-03-06 13:18:24,141 - softwarecenter.db.categories - WARNING - '/usr/share/desktop-directories/Education.directory' has no name
Traceback (most recent call last):
  File "/usr/bin/software-center", line 182, in <module>
    app.run(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1387, in run
    self.show_available_packages(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1325, in show_available_packages
    self.view_manager.set_active_view(ViewPages.AVAILABLE)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 151, in set_active_view
    view_widget.init_view()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 139, in init_view
    SoftwarePane.init_view(self)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/softwarepane.py", line 138, in init_view
    self.icons, self.show_ratings)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/appview.py", line 70, in __init__
    self.helper = AppPropertiesHelper(db, cache, icons)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/models/appstore2.py", line 108, in __init__
    self.all_categories = cat_parser.parse_applications_menu()
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 277, in parse_applications_menu
    category = self._parse_menu_tag(child)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 471, in _parse_menu_tag
    query = self._parse_include_tag(element)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 429, in _parse_include_tag
    xapian.Query.OP_AND)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 366, in _parse_and_or_not_tag
    operator_elem, xapian.Query(), xapian.Query.OP_OR)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 412, in _parse_and_or_not_tag
    q = self.db.xapian_parser.parse_query(s,
  File "/usr/share/software-center/softwarecenter/db/database.py", line 185, in xapian_parser
    xapian_parser = self._get_new_xapian_parser()
  File "/usr/share/software-center/softwarecenter/db/database.py", line 211, in _get_new_xapian_parser
    xapian_parser.set_database(self.xapiandb)
  File "/usr/share/software-ce...

The problem is this.

At the beginning of /usr/share/software-center/softwarecenter/config.py, it imports either configparser or ConfigParser based on what will import, apparently based on the incorrect belief that "configparser" is for Python3 while "ConfigParser" is Python2.7:

try:
    from configparser import SafeConfigParser
    SafeConfigParser # pyflakes
except ImportError:
    from ConfigParser import SafeConfigParser

So the background is that Python2.x has "ConfigParser" and Python3 has "configparser". Yes, that's kind of weird. In Python3, they decided to standardize on lower-case package names, so ConfigParser became configparser.

The problem is, Software Center's developers didn't realize that the classes also changed somewhat. Example:

Python 2.7.3 (default, Sep 26 2012, 21:51:14)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import configparser, ConfigParser
>>> issubclass(configparser.SafeConfigParser, object)
True
>>> issubclass(ConfigParser.SafeConfigParser, object)
False

Software Center is crashing because ConfigParser and configparser are not identical and apparently, it was just assumed that they were. What I'm not sure is why this only affects a handful of people. Perhaps our ppa's have forced an upgrade in Python that Software Center wasn't tested against. At any rate, here's a patch.

Actually, I should clarify:

> incorrect belief that "configparser" is for Python3 while "ConfigParser" is Python2.7

That belief is correct. The assumption that's not correct is that they are otherwise identical. They are not.

Also, I don't see my patch that I attached. Weird. Here it is, in plaintext:

--- /usr/share/software-center/softwarecenter/config.py.orig 2013-04-03 00:04:17.852950494 -0600
+++ /usr/share/software-center/softwarecenter/config.py 2013-04-03 00:16:34.680963943 -0600
@@ -29,8 +29,15 @@

 LOG = logging.getLogger(__name__)

+# See https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/1038429
+if issubclass(SafeConfigParser, object):
+ class BaseSoftwareCenterConfig(SafeConfigParser):
+ pass
+else:
+ class BaseSoftwareCenterConfig(SafeConfigParser, object):
+ pass

-class SoftwareCenterConfig(object, SafeConfigParser):
+class SoftwareCenterConfig(BaseSoftwareCenterConfig):

     SECTIONS = ("general", "reviews")

Hmmm. Didn't paste right with indentation. Sorry about this, I don't know why it won't show my attachment. Here's a pastebin:

http://pastebin.com/bnmmRqff

Just to chime in with my take on this problem:

Running on Ubuntu 13.04, I have an Python 2.7-based app that relies on the back-ported (from 3.x) "configparser" module (https://pypi.python.org/pypi/configparser)

After I do a "sudo pip install configparser", I get the behavior noticed above when software-center runs.

If I uninstall configparser via pip, the problem goes away.

Using Peter Johnson's fix/hack in #3, I have a temporary fix for this.

To chime in, the fix in #3 also temporarily allows me to get by.

This is now blocking image builds, because the python-configparser package is newly pulled into those by python-configglue.

Hey Rodney,

We noticed that this error is happening on dist-upgrades in current Saucy, and also for CD image builds - making both fail.

python-configglue as of the latest upgrade is pulling in python-configparser (this is a dep of ubuntunone-client) which exposes the bug in software-center.

There's some analysis here - could you see if you agree with any of it or have a solution of your own to propose? From my side I wonder if inheriting object there is necessary but I don't know the code.

If you need some sponsorship then please ping me; this is one that's good to fix quite quickly.

Thanks.

This bug was fixed in the package software-center - 13.05-0ubuntu2

---------------
software-center (13.05-0ubuntu2) saucy; urgency=low

  * debian/patches/01_bzr-fix-1038429.patch:
    - Don't use MI, and use super to call the parent __init__. (LP: #1038429)
 -- Rodney Dawes <email address hidden> Fri, 05 Jul 2013 17:39:12 -0400

Geez da hell is a normal user supposed to do? Not install any software for a few months (until this is released)? Shit like this is why we still aren't anywhere close to the "Year of Linux Desktop".

https://bitbucket.org/ambv/configparser/issue/5/installing-configparser-is-dangerous

While this lists out as the fixed has been released, I did an update today and the issue still exists with the Ububtu Software Center failing to open. Can you maybe give us a command line to try so that we can manually install the fix?