Thank you so much for using time on this issue.
I`m today using Mac, but I will by a new machine to connect to Linuxprograms as soon as I have time and energy to follow up.
Br,
Svein

> Date: Mon, 17 Dec 2012 17:43:35 +0000
> From: <email address hidden>
> To: <email address hidden>
> Subject: [Bug 886273] Re: Poor handling of broken sources.list files
> 
> I'm going to work on a detailed design for this, but here's what I'm
> thinking so far:
> 
> If Software Updater does an automatic check, OR you launch it manually,
> OR you launch Ubuntu Software Center, when sources.list is invalid,
> then:
> 
> a. aptdaemon puts up a dialog explaining the problem and illustrating
> how it can fix it for you
> 
> b. if you choose to fix it, an error tracker dialog appears giving you
> the option to report the error
> 
> c. the program launches as normal.
> 
> Perhaps (a) and (b) should be around the other way. Or perhaps they can
> be merged by introducing a new variation of the RecoverableError dialog.
> 
> -- 
> You received this bug notification because you are subscribed to a
> duplicate bug report (108601).
> https://bugs.launchpad.net/bugs/886273
> 
> Title:
>   Poor handling of broken sources.list files
> 
> Status in “aptdaemon” package in Ubuntu:
>   Confirmed
> Status in “software-center” package in Ubuntu:
>   New
> Status in “update-manager” package in Ubuntu:
>   Triaged
> 
> Bug description:
>   Ubuntu Software Center 2.1.16.1, Ubuntu Maverick
>   Ubuntu Software Center 5.1.11, Ubuntu 12.04 beta 1
> 
>   1. echo "deb http://ppa.launchpad.net/tualatrix/ppa/ubuntu main #Ubuntu Tweak Stable Source" | sudo tee /etc/apt/sources.list.d/ubuntu-tweak-stable.list
>   2. software-center
>   3. update-manager
> 
>   What happens:
>   2. ----------
>   Traceback (most recent call last):
>     File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 222, in open
>       self._cache = apt.Cache(GtkMainIterationProgress())
>     File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 102, in __init__
>       self.open(progress)
>     File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 145, in open
>       self._cache = apt_pkg.Cache(progress)
>   SystemError: E:Malformed line 1 in source list /etc/apt/sources.list.d/ubuntu-tweak-stable.list (dist parse), E:The list of sources could not be read., E:The package lists or status file could not be parsed or opened.
>   2012-03-12 10:52:15,573 - softwarecenter.db.enquire - ERROR - _get_estimate_nr_apps_and_nr_pkgs failed
>   Traceback (most recent call last):
>     File "/usr/share/software-center/softwarecenter/db/enquire.py", line 115, in _get_estimate_nr_apps_and_nr_pkgs
>       tmp_matches = enquire.get_mset(0, len(self.db), None, xfilter)
>     File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 74, in __call__
>       if (not pkgname in self.cache and
>     File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 241, in __contains__
>       return self._cache.__contains__(k)
>   AttributeError: 'NoneType' object has no attribute '__contains__'
>   Traceback (most recent call last):
>     File "/usr/bin/software-center", line 176, in <module>
>       app.run(args)
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1279, in run
>       self.show_available_packages(args)
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1208, in show_available_packages
>       self.view_manager.set_active_view(ViewPages.AVAILABLE)
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 148, in set_active_view
>       view_widget.init_view()
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 157, in init_view
>       self.apps_filter)
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 234, in __init__
>       self.build(desktopdir)
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 476, in build
>       self._build_homepage_view()
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 253, in _build_homepage_view
>       self._append_whats_new()
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 415, in _append_whats_new
>       whats_new_cat = self._update_whats_new_content()
>     File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 404, in _update_whats_new_content
>       docs = whats_new_cat.get_documents(self.db)
>     File "/usr/share/software-center/softwarecenter/db/categories.py", line 120, in get_documents
>       nonblocking_load=False)
>     File "/usr/share/software-center/softwarecenter/db/enquire.py", line 316, in set_query
>       self._blocking_perform_search()
>     File "/usr/share/software-center/softwarecenter/db/enquire.py", line 211, in _blocking_perform_search
>       matches = enquire.get_mset(0, self.limit, None, xfilter)
>     File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 74, in __call__
>       if (not pkgname in self.cache and
>     File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 241, in __contains__
>       return self._cache.__contains__(k)
>   AttributeError: 'NoneType' object has no attribute '__contains__'
>   ------------
> 
>   3. A dialog is displayed with something along these lines:
>   ------------
>   Could not initialize the package information
>   An unresolvable problem occurred while initializing the package information.
>   Please report this bug against the 'update-manager' package and include the following error message:
>   'E:Type 't/screenlets/ppa/ubuntu' is not known on line 3 in source list /etc/apt/sources.list.d/screenlets-ppa-oneiric.list'
>   ------------
>   And an obese menu appears in the corner of the screen. <http://imgur.com/a/pgGEf#2>
> 
>   
>   Besides the duplicates marked here, there are dozens of bug reports with particular examples of malformed sources.list, such as bug 128775, bug 163933, bug 164135, bug 176253, bug 183861, bug 241154, bug 311399, bug 350373, bug 358587, bug 416872, bug 432318, bug 470589, bug 617232, bug 617998, bug 677698, bug 728258, bug 753253, bug 799600, bug 830588, bug 835258, bug 879221, bug 880661, bug 886641, bug 890138, bug 927987, bug 947296, bug 981357, bug 1008359, bug 1009618, and bug 1063099.
> 
>   Often these bug reports are marked as Incomplete or Invalid, or
>   converted into questions, on the grounds that the user must have
>   edited sources.list themselves. But Ubuntu should be robust enough to
>   repair problems like this itself.
> 
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