[SOLVED] "Update Manager" won't run; Pango broken

[Valacosa]

I am currently running Ubuntu 7.10 (Gutsy Gibbon) and would like to upgrade to Ubuntu 8.04.1 LTS (Hardy Heron). But my problem is Update Manager doesn't run. At all. If I click the icon in the System->Administration menu, nothing happens.

I also tried running the update manager from the console, using the command:
gksu "update-manager -c -d"
And I get the following error:
ImportError: could not import pango
k-2.0/gtk/__init__.py:48: RuntimeWarning: tp_compare didn't return -1 or -2 for exception
ImportError: could not import pango
Traceback (most recent call last):
File "/usr/bin/update-manager", line 29, in <module>
import gtk.glade
ImportError: cannot import name Widget from gtk

My problem is exactly the same as described in the Ubuntu forums post here (http://ubuntuforums.org/showthread.php?t=420782), but no solution is attached. Also, the packages named in this solution (http://ubuntuforums.org/showthread.php?t=540938) aren't available anymore.

This post (http://ubuntuforums.org/archive/index.php/t-123415.html) had some suggestions which helped me narrow down the problem. If I load python and try to import Pango, this is what happens:
Python 2.5.1 (r251:54863, Jul 31 2008, 23:17:40)
[GCC 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pango
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: /var/lib/python-support/python2.5/gtk-2.0/pango.so: undefined symbol: pango_gravity_get_for_matrix
>>>

So update-manager seems to not work because Python can't import Pango. What's more, I downloaded the alternate-installation CD in an attempt to follow the non-network upgrade instructions here (http://www.ubuntu.com/getubuntu/upgrading-8.04), but cdromupgrade doesn't work either!

Is there a fix out there? I'd really rather not nuke my system and start from scratch.

Things I have already tried:

Setting the environment variable PYTHONPATH
Reinstalling libpango1.0-common, libatk1.0-1, and a host of other packages

[Valacosa]

Well, I fixed it. Thanks for all the help, guys. *cricket*

Seriously though, it's all working again. update-manager works, pygtk-demo works, and mupen64 works. If any GTK+ or GLADE application stops working, and you have reason to believe Pango is at fault, here's what I did to solve the problem.

First, I found out what version of Pango I had installed. You can do this with the command
dpkg -l libpango1.0-common
You'll get a response like this:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
+++-==================-==================-================================================== ==
ii libpango1.0-common 1.18.3-0ubuntu1 Modules and configuration files for the Pango


Then I navigated to the Pango website, here (http://www.pango.org/). Their download section (http://ftp.gnome.org/pub/GNOME/sources/pango/) has pretty much every version ever released. I saw that I had 1.18.3 installed, so I grabbed that one.

Do not download the latest version. The latest version of Pango will depend on the latest version of Cario, GTK+, and a bunch of other things you probably don't have. If you download the version you supposedly already have installed, compiling will be a lot easier.

That's right, we're going to compile this sucker. It's pretty easy, though, in the best case scenario. Once I unzipped the tarball, all I had to do is change to the directory with the source code in it and type three magic commands:

./configure
make
sudo make install

I don't consider this an optimal solution. If you don't already have any of the GNOME development tools installed, the configure script will probably complain until you install them. And this solution requires you to be at least a little comfortable in the shell. But it solved the problem for me, maybe it'll work for you.