As most of you know, KDE 3.5 is getting off the Gentoo train for various reasons mentioned elsewhere (in short: security, lack of upstream interest).
Some people are still using it though and they have been asking how they can keep it on their system, without emerge screaming each time they try to update world.
I’m writing this post to guide those people (you? 
) on how they can achieve that.
1. Adding the kde-sunset overlay
Perhaps the most important thing you need to remember is that the ebuilds will be completely removed from the tree, so you need to add an overlay called kde-sunset to portage which contains a copy of most of them.
To add the overlay you need to have layman with git USE flag enabled:
USE="git" emerge -av layman
make sure you add the git USE flag in your package.use or make.conf
you can then use layman to install the overlay:
layman -f
layman -a kde-sunset
if this is your first time using layman, you’ll have to add the following line @ the end of your make.conf:
source /usr/local/portage/layman/make.conf
you can keep the overlay updated by running:
layman -s kde-sunset
2. KDE 3.5 is masked (this is necessary only while KDE 3.5 is still in tree)
Now we have the overlay, but until KDE 3.5 is completely wiped off the tree, there’s a mask to warn users about it.
Portage will scream about this mask each time you try to emerge so you need to unmask KDE 3.5 manually.
There are two (and a half) ways to do this:
a1) if your package.unmask is a folder, symlink the unmask file from kde-sunset to /etc/portage/package.unmask/
ln -s /usr/local/portage/layman/kde-sunset/Documentation/package.unmask/kde-3.5 /etc/portage/package.unmask/kde-3.5
a2) if your package.unmask is not a folder you can append the file (but you’ll have to update it manually)
cat /usr/local/portage/layman/kde-sunset/Documentation/package.unmask/kde-3.5 >> /etc/portage/package.unmask
b) if you don’t like all that, you can emerge autounmask
emerge -av autounmask
and ask it to unmask stuff for you – note that autounmask doesn’t like :slot and will only work with -version
autounmask kde-meta-3.5
3. I don’t want KDE 4 (yet)
So all is great now but portage wants to install KDE 4 when you emerge world.
This is happening because KDE 4 went stable recently and portage thinks you want to upgrade (you should btw 
).
To fix this one we need to tell portage that we actually want the 3.5 version of KDE and we don’t care about 4.
we need to edit /var/lib/portage/world and add a version (or a slot) to every kde 3.5 app we have in there.
* be careful with this file *
for example, lets say that you installed kde 3.5 using the kde-meta ebuild.
if you open /var/lib/portage/world you’ll find a line saying
kde-base/kde-meta
you need to add :3.5 which is the 3.5 slot, or -3.5.10 which is the version (or both, version first) at the end. if you add the version, you’ll have to prepend a “=” as well.
the line should now read:
kde-base/kde-meta:3.5
do this for each KDE 3.5 app you have in the world file. If you’re unsure of the slot/version, use eix packagename to find it out.
4. All systems go
emerge -avDuN world
^^ this should now be clean of any KDE 4 traces and mask warnings
If you have any issues or are interested in maintaining kde-sunset, you may visit us over @ #gentoo-kde in freenode’s IRC network or drop us an email at kde _at_ gentoo _dot_ org. We’ll do our best to help you
Maybe after reading this post your KDE 3 installation will last a bit longer
Enjoy and see you w/ KDE 4 soon 
Im wondering why a kde-4 – mask file wouldn’t be enough to prevent portage from being upgrading it.
That would be an option as well, yeah
Thanks a lot for this page !
I’m very happy with 3.5 at work and I do not want to change.
(I use 4.x at home, and I think it is not yet ready)
Thank you for this. I tried adding >=kde*-4 to package.mask but it still insisted on KDE4. Now it shows KDE3 again. Yay.
I finally tried KDE4 when it went “stable”, but it has lowered my productivity dramatically and doesn’t seem entirely stable to me. I really miss the independent desktops on my dual screens, too.
Thank you, thank you. KDE 4.3.1-r1 didn’t get the expected acceptance at work, so I needed to downgrade to KDE 3.5.10.
Thanks for that layman explanation, but I still wonder why I get this mysterious kopete compile errors and why this tool is needed by kde-network-meta (when using kde-meta as main package)…, I’ll file a bug and will see what happens.
This trick chopped my /etc/portage/package.mask and /etc/portage/package.unmask down to almost nothing. Thanks for that.
Now to get kitchensync to finish setting up.
Blessed be!
Pappy
Thank you oh so much for posting this easy to follow guide. I have been avoiding a general update of my system to KDE4 for a long time now because KDE4 is for me a disaster. Even as I tried KDE 4.3.3, which is supposed to be stable, I had application crashes and horrible performance problems.
Last year I built a 64 bit system with 4Gb ram and an AMD 64 X2 dual core 5000+ cpu. It’s fast, things responded in the blink of an eye, as I expect them to. It was like having a ferrari. Then I tried KDE 4 on it, and it was horribly slow, like putting a 25 ton trailer on the ferrari.
I for one will not be going to KDE4 any time soon, it’s just too much of a resource hog, too slow, and too unstable.
I really do not understand why portage maintainer removed KDE3.5 from portage, KDE4 is not stable, application crash is normal for KDE4. Its completely unstable. Thank you very much for this guide which will help me to remove KDE4 and install KDE3.5 again. I think KDE4 will need at least 2-3 years to meet level of stability acceptable for me.
Thanks a lot! I already thought about switching to a different window manager or even Crux or some other do-it-all-yourself-distro because Gentoo insisted on KDE4… KDE4 messed up my keyboard (yeah, that’s right, under KDE4 my keyboard doesn’t work like usual o.O ), I can’t set up all the shortcuts I want… I used to have win+c to fire up konsole, win+h to open home in konqueror, win+s to open the start menu… just to name a few… more than 50% of my shortcuts can’t be set anymore or don’t work any longer… and I don’t need or want that plasma thing… I want a clean, oldschool desktop… and I want my Amarok-1.4 back, Amarok2 sucks hard
KDE4 is just some semi-functional bloated Krap
thanks again for explaining how to stick to KDE3 on my favourite distro!
I will think about using KDE4 once someone shows me that keyboards work like they should, that I can set and use(!) all my shortcuts again, that it can be made look like KDE3 and that Amarok2 is useable or Amarok1 is supported
Hi…I have a question.I try to install the package gtk-engines-qt …but there isnt this packages for kde 3.5 in “KDE-SUNSET”….Why??
Did a sync today, there are several packages that have been masked that are needed for kde3, koffice, kphotoalbum. Even the kdelibs now appear to be masked!!!
‘!!! All ebuilds that could satisfy “kde-base/kdelibs:3.5″ have been masked.”‘
What do we do now??? HELP!!!!! I don’t want KDE4!!!!
First off thank you Alex for the overlay! I manage around 200 KDE Desktops off of 1 server and a recent upgrade to KDE4 did not go down well. I franticly searched for a way to downgrade to KDE-3.5 and came across this posting which was effortless.
My setup is a bit different as it is configured for a work environment so there is no multimedia, I use split-ebuilds, but managed to get the desired KDE configuration. Anybody else who is using split-ebuilds and required assistance with using this overlay I will be happy to assist.
Lastly I noticed that the kiosktool is not included in the sunset portage, is there any possibility of including it, I rely greatly on it.
Thanks again,
Dyllan