Software center does not start [dbus.proxies - ERROR - Introspect error]

Hello,

  Thanks for reporting this. Are you using a proxy?

  Seems a duplicate of bug #976533.

I'm not sure how to check that.

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

Based on https://bugs.launchpad.net/ubuntu/+source/computer-janitor/+bug/715707 , this issue seems to be with python/dbus and is not specific to software center.

I used to get the same exception. Running /usr/lib/ubuntu-sso-client/ubuntu-sso-login manually resulted in the following exception:

Traceback (most recent call last):
  File "/usr/lib/ubuntu-sso-client/ubuntu-sso-login", line 66, in <module>
    from ubuntu_sso.main import main
  File "/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/main/__init__.py", line 96, in <module>
    from ubuntu_sso.main import linux as source
  File "/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/main/linux.py", line 464, in <module>
    from ubuntu_sso.main import qt
  File "/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/main/qt.py", line 39, in <module>
    from PyQt4 import QtCore
RuntimeError: the sip module implements API v9.0 to v9.1 but the PyQt4.QtCore module requires API v8.1

It seemed to be a problem with python-sip and python-qt4. Re-installing both packages fixed it for me.

I have the same bug after installing Ubuntu 13.04.

I have tried to uninstall software-center and install it again, it didnt fix it.

Basically I have uni stalled the operating system and reinstalled it.
Problem solved!

________________________
Lee G. Madeley (M.Sc.)
* 072 187 9821** *

On Fri, Apr 26, 2013 at 4:30 PM, Danloaiza <email address hidden> wrote:

> I have the same bug after installing Ubuntu 13.04.
>
> I have tried to uninstall software-center and install it again, it didnt
> fix it.
>
> --
> You received this bug notification because you are subscribed to a
> duplicate bug report (1125176).
> https://bugs.launchpad.net/bugs/1068680
>
> Title:
> Software center does not start [dbus.proxies - ERROR - Introspect
> error]
>
> Status in Ubuntu Single Sign On Client:
> New
> Status in “dbus-python” package in Ubuntu:
> Confirmed
>
> Bug description:
> If I type
> software-center
> in the terminal, I get the following error and the program do not start:
> 2012-10-19 11:47:14,260 - softwarecenter.ui.gtk3.app - INFO - setting up
> proxy 'None'
> 2012-10-19 11:47:14,369 - softwarecenter.db.database - INFO - open()
> database: path=None use_axi=True use_agent=True
> 2012-10-19 11:47:17,104 - softwarecenter.fixme - WARNING - logs to the
> root logger: '('/usr/lib/python2.7/dist-packages/dbus/proxies.py', 410,
> '_introspect_error_handler')'
> 2012-10-19 11:47:17,104 - dbus.proxies - ERROR - Introspect error on
> com.ubuntu.sso:/com/ubuntu/sso/credentials: dbus.exceptions.DBusException:
> org.freedesktop.DBus.Error.Spawn.ChildExited: Process
> /usr/lib/ubuntu-sso-client/ubuntu-sso-login exited with status 1
> Traceback (most recent call last):
> File "/usr/bin/software-center", line 130, in <module>
> app = SoftwareCenterAppGtk3(options, args)
> File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line
> 337, in __init__
> self.icons)
> File
> "/usr/share/software-center/softwarecenter/ui/gtk3/session/appmanager.py",
> line 66, in __init__
> self.oauth_token = helper.find_oauth_token_sync()
> File "/usr/share/software-center/softwarecenter/backend/ubuntusso.py",
> line 139, in find_oauth_token_sync
> sso.find_credentials()
> File
> "/usr/share/software-center/softwarecenter/backend/login_impl/login_sso.py",
> line 75, in find_credentials
> self.proxy.find_credentials(self.appname, self._get_params())
> File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 70, in
> __call__
> return self._proxy_method(*args, **keywords)
> File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 145, in
> __call__
> **keywords)
> File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 651,
> in call_blocking
> message, timeout)
> dbus.exceptions.DBusException:
> org.freedesktop.DBus.Error.Spawn.ChildExited: Process
> /usr/lib/ubuntu-sso-client/ubuntu-sso-login exited with status 1
>
> ProblemType: Bug
> DistroRelease: Ubuntu 12.10
> Package: software-center 5.4.1.2
> ProcVersionSignature: Ubuntu 3.5.0-17.28-generic 3.5.5
> Uname: Linux 3.5.0-17-generic i686
> ApportVersion: 2.6.1-0ubuntu3
> Architecture: i386
> Date: Fri Oct 19 11:48:12 2012
> InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release i386
> (20121017.2...

I can confirm den.t 's analysis and recommended fix (above).

I am a programmer, and futzed with sip and pyqt (downloaded and built a later version than is provided by Ubuntu) and then suffered this problem.

If Ubuntu depends so much on Python, Qt, and PyQt, should it sandbox them from developers?

See a related fix:

https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/1085425/comments/18