Ubuntu Karmic fail: Pidgin and the new Empathy won't run in some cases until you make this fix

I haven't loaded up an IM client since I upgraded from Ubuntu 9.04 (Jaunty) to Ubuntu 9.10 (Karmic).

But I did today, and neither Pidgin nor the new GNOMEish Empathy would run. (Whether this matters or not, I upgraded from Ubuntu 9.04 to 9.10, as opposed to doing a reinstall.)

I started both IM clients in the terminal to see if I could determine what the problem might be:

steven@toshiba-ubuntu:~$ pidgin
ERROR: Could not load classifier cascade /usr/share/opencv/haarcascades/haarcascade_frontalface_alt2.xml
Illegal instruction
steven@toshiba-ubuntu:~$ empathy
ERROR: Could not load classifier cascade /usr/share/opencv/haarcascades/haarcascade_frontalface_alt2.xml
Error re-scanning registry , child terminated by signal
Run 'empathy --help' to see a full list of available command line options.

(empathy:2527): empathy-WARNING **: Error in empathy init: Error re-scanning registry , child terminated by signal
steven@toshiba-ubuntu:~$

At least both apps seem to be suffering from the same problem, and luckily there is already a bug (#459940) on it in Launchpad. The bug is for the package opencv, and

According to notes on the bug, other GNOME applications affected by the problem include the Totem video player, the Brasero disc burner and Rhythmbox music player.

I can confirm that on my system, every one of those apps will not run.

I also confirmed that the XML file in question is NOT on my box:

steven@toshiba-ubuntu:~$ cat /usr/share/opencv/haarcascades/haarcascade_frontalface_alt2.xml
cat: /usr/share/opencv/haarcascades/haarcascade_frontalface_alt2.xml: No such file or directory

One of the comments in the bug report says:

Thomas DEBESSE wrote on 2009-10-29: #6

seems to appear when installing frei0r-plugins (example: for kdenlive). When removing frei0r-plugins from my karmic I've no error messages at all, and totem (and other apps) runs fine.

Hey, I do have KDEnlive on this laptop. I would've removed the offending plugins package, but I decided first to do a software update to see if Ubuntu's package maintainers took care of the problem.

I opened a terminal and used aptitude to do it:

steven@toshiba-ubuntu:~$ sudo aptitude update
[sudo] password for steven:

Reading package lists... Done

(listing of mirrors hit has been removed for brevity)

steven@toshiba-ubuntu:~$ sudo aptitude upgrade
W: The "upgrade" command is deprecated; use "safe-upgrade" instead.
Reading package lists... Done
Building dependency tree
Reading state information... Done
Reading extended state information
Initializing package states... Done
The following packages will be upgraded:
binutils brasero empathy empathy-doc f-spot libbrasero-media0
libempathy-common libempathy-gtk-common libempathy-gtk28 libempathy30
nvidia-common python python-minimal ubuntu-xsplash-artwork xsplash
15 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 5,715kB of archives. After unpacking 160kB will be freed.
Do you want to continue? [Y/n/?]

That seems like it would take care of the problem, but the missing file still hadn't shown up. Would a reboot fix things?

After the software update didn't solve the problem, I decided to go into the Synaptic Package Manager and reinstall the opencv packages, which I guessed were libcv1, libhihgui1 and libcvaux1.

That didn't work either.

The next step would be either removing KDEnlive or the offending package, frei0r-plugins.

I went into Synaptic and removed frei0r-plugins.

Nothing changed.

I reinstalled the three opencv libraries (libcv1, libhihgui1 and libcvaux1).

That worked. I was able to run Pidgin, Empathy (which has a nice dialog that offered to import my Pidgin settings, an offer I accepted), Rhythmbox, Brasero and Totem once again.

And KDEnlive seemed to be working, too. It at least loaded.

Let's review: If Pidgin, Empathy, Rhythmbox, Brasero and Totem are not running on your Ubuntu 9.10 system, first update the box, then use the Synaptic Package Manager to remove frei0r-plugins and reinstall libcv1, libhihgui1 and libcvaux1.

I'm a bit surprised that the software update alone didn't fix the problem. While the fix is easy, it's a little bit of "dependency hell" for a package-management system (apt) that is not supposed to suffer from that particular malady.

While I've solved my X issue and now this in 9.10, I probably should have waited an extra month or so before upgrading so these bugs could be shaken out.

Bug #459940 should be closed eventually, but at present it appears that the removal of the offending package and the replacement of those the offender affected is the way out of this problem.

I do have a Launchpad account (I had to create it in order to buy stuff at the Canonical U.S. shop), and I subscribed to this bug so I can keep an eye on it.

I've seen a lot of comments directed at me and others in regard to reporting bugs, and following this bug is hopefully a step in that direction for me personally as a Ubuntu user.