In less than 48 hours Ubuntu Jaunty Jackalope will be released officially! While using Jaunty for more than a month I am pleased to see this great new release getting it’s way to a huge usership. While preparing my small „new features in Ubuntu Jaunty Jackalope“ talk for the „Ubuntu Berlin“ release party at c-base, I’d like to point out one open bug, that will make it into the release and might get some users into strange trouble:
When you have – for whatever reason (either by chance, clicking around or due to having a rotated display) – changed the display mode of Ubuntu to VRGB or VBGR (you can easily do this in the „System>Preferences>Appearance>Fonts“ menu) and additionaly turned on the lcd/subpixel mode, probably all of your qt4 applications – even qtconfig – will be totatlly scrambled and unreadable. The bug might hit you under Ubuntu (without a blue „K“ in the beginning) as you probably run something like VirtualBox, Skype or even Amarok in your Gnome environment. It will probably look like this:
Screenshot showing the scrambled qt application
But: Don’t panic! This bug only occurs when you changed some defaults in the Appearance/Fonts settings to rather uncommon or often maybe useless settings and switching back is fairly easy. But as I ran into this and put some effort into the corresponding bug on launchpad Subpixel/Lcd mode with VRGB/VBGR makes qt4 applications on Jaunty unreadable, I noticed, that a remarkable bunch of users posted duplicate bug reports or commented the report.
So if you are running into this error, all you have to do, is:
- exit all qt applications,
- go into „System>Preferences>Appearance>Fonts“,
- change VRGB/BGR to RGB/BGR.
That’s all. If you want to examine the bug, do the following (don’t do this at home):
- exit all qt applications,
- go into „System>Preferences>Appearance>Fonts“,
- change RGB/BGR to VRGB/BGR,
- switch to lcd/subpixel mode.
Afterwards your qt applications will look scrambled. If you don’t know, which one to run for a test, you probably have „qtconfig“ installed.
(I had a little chat with some developers about the severity of this bug. Though I think it’d would be definitely better not having it in a release, I understand the point, that the environment must be set up in a rather special way to run into this and it popped up quite late. Therefore it did not make it into the release critical bugs, but I am quite sure, it will be fixed soon.)
That’s all about this. I wish you a smooth upgrade to Jaunty – see you there 
[update 2009-04-03]
As you can read on https://bugs.launchpad.net/ubuntu/+source/qt4-x11/+bug/334657, a patch has been committed to the Ubuntu repositories, that has been found here:
So the fix as an update is coming closer…
It is sad to see that this bug isn’t release critical. After a long term hassle (5 yrs) with Gentoo, a short term flirt (1/4yr) with Arch, I finally arrived at Ubuntu in the hope of more stability on my workspace. VRGB mode is critical to anyone using a rotated display (try xrandr -o left).