Steps to reproduce: - install multiple slotted packages - KDE 4.1 is good example (SLOT=4.1 with -kdeprefix so that inter-SLOT upgrade will be applied) - issue upgrade to KDE 4.2 (SLOT=4.2) - this will applu some blocks and will explicitly cause some packages to be uninstalled (as they are no longer present in 4.2 and wouldn't be uninstalled otherwise) - terminate process at some point This will leave (as of now) some duplicated package atoms installed - like (arbitrary example): kde-base/solid-4.1.4 kde-base/solid-4.2.0 kde-base/libplasmaclock-4.1.4 kde-base/libplasmaclock-4.2.0 as uninstall process for those -4.1.4 has been delayed and upgrade process has been terminated before it got there thus leaving system in a bit inconsistent state. Of course one can fix this by --depclean as 4.1.4 are no longer referenced. This may not be only inter-SLOT related issue, but just issue related to explicit blocks, are they cause some packages to be explicitly uninistalled.
I haven't seen this problem in a while. Maybe close it as worksforme, I'll reopen if it appears again.
Well, unless you'd like to provide 'atomic installation' feature...
There's this fix for executing uninstalls as soon as possible: http://git.overlays.gentoo.org/gitweb/?p=proj/portage.git;a=commit;h=6c54b8b0d6d12f40f5172f573d7d030eafeaa9b0 This is a lot less likely to be an issue now that kdeprefix is gone (and all kde-4 packages have moved to SLOT=4).
*** Bug 537080 has been marked as a duplicate of this bug. ***
Haven't seen this in ages. I'll reopen if I ever spot it again.
