After last sync it's impossible to set kdeprefix use flag. It appears to be masked.
# emerge -vp kdelibs
These are the packages that would be merged, in order:
Calculating dependencies... done!
[ebuild U ] kde-base/kdelibs-4.2.4-r3 [4.2.4-r1] USE="acl alsa bzip2 handbook mmx nls opengl semantic-desktop spell sse sse2 ssl -3dnow (-altivec) -bindist -debug -doc -fam -jpeg2k (-kdeprefix*) -kerberos -openexr -test -zeroconf" 0 kB 
[ebuild U ] kde-base/kdebase-data-4.2.4-r1 [4.2.4] USE="(-kdeprefix*)" 0 kB [1=>0]
[ebuild R ] kde-base/kde-env-4.2.4 USE="(-kdeprefix*)" 0 kB [1=>0]
Steps to Reproduce:
This was decided on the last KDE team meeting one June 18th as a step towards stabilizing kde4, as kdeprefix caused numerous problems for users. Those who really need it can unmask it in /etc/portage/profile — read man portage for more details.
As explained above,
this bug is invalid.
Yeah, and kept open for a reason, guess what :)
Can I unmask the kdeprefix?
During the last update on my system (emerge -uDNav @system @world), some packages (kdelibs, kde-env and a few others) got re-merged with USE=-kdeprefix, while most did not. (I imagine this is a separate Portage bug.)
This left KDE on my work machine in an unusable state. (KDM couldn't even start, because it could no longer find its greeter plugin.) I'm rebuilding now with +kdeprefix, but I estimate I've lost at least an hour to this so far and will lose a couple more as kdelibs et al rebuilds.
I appreciate the massive amount of time and effort you guys have put in to produce a set of working, flexible KDE ebuilds for Gentoo. I must say that until now, I've been impressed with their quality and stability. I've gotten used to updates not breaking my system -- my mistake for not looking at emerge -p more closely. ;)
But frankly, springing this change on users unannounced is unacceptable (to me, anyway -- I can't speak for anyone else). It's a very large change, and has resulted in at least one broken machine. The very least you could do is warn users, loudly, ahead of time that this change is coming, it may cause breakage, and explain what to do if it does.
In the meantime, please revert this change immediately. Thank you.
It's trivial to unmask it if you really need to. I don't, however, think the decision to mask kdeprefix was a good one, as I've never had any problems with it and use it to keep kde3 and kde4 unaware of each other. It's even disabled by default.
The guide has been updated, with a full explanation of pros and cons of kdeprefix, and the reasons that it is masked. I'm closing this bug.
Thank you for updating the documentation.
I do want to repeat, however, that I feel a change as invasive as this one requires advance notice. I hope the next time such a change needs to be made, the Gentoo KDE team will take this into consideration.
I was away at the last meeting and since i usually take care of those kde pr issues, i was unaware of the masking of kdeprefix use flag. Also i was busy with my exams...
But of course that isn't an excuse, someone should have announced and documented that change. Nevertheless i'm writing an eselect news item right now to announce the guide, since it covers the kdeprefix issue as long as the problem with monolithic ebuilds in kde3. Thanks and sorry for the mess
Thanks, Theo. Fortunately all it took for me was an overnight rebuild with -kdeprefix and everything is happy again. (Stuff not getting rebuilt properly before turned out to be my fault -- I was missing some packages in @world. >.>)
Like I said earlier, I really appreciate all the work you guys put into packaging KDE for Gentoo.
There realy should be some kind of warning (big and fat) if you're upgrading some packages to -kdeprefix and some packages stay kdeprefix. This crashed a friends system and now he wants to switch back to windows. Mission accomplished.