Still emerging. A bit of a hiccup after 228 packages of 594 emerged just fine, then libwpg borked. Just for future googlers:
from portage's summary.log:
>>> Messages generated by process 3072 on 2016-02-12 18:42:08 GMT for package app-text/libwpg-0.3.1:
ERROR: preinst
This package will overwrite one or more files that may belong to other
packages (see list below). You can use a command such as `portageq
owners / <filename>` to identify the installed package that owns a
file. If portageq reports that only one package owns a file then do
NOT file a bug report. A bug report is only useful if it identifies at
least two or more packages that are known to install the same file(s).
If a collision occurs and you can not explain where the file came from
then you should simply ignore the collision since there is not enough
information to determine if a real problem exists. Please do NOT file
a bug report at http://bugs.gentoo.org unless you report exactly which
two packages install the same file(s). See
http://wiki.gentoo.org/wiki/Knowledge_Base:Blockers for tips on how to
solve the problem. And once again, please do NOT file a bug report
unless you have completely understood the above message.
Detected file collision(s):
/usr/lib64/pkgconfig/libwpg-0.3.pc
/usr/include/libwpg-0.3/libwpg/WPGraphics.h
/usr/include/libwpg-0.3/libwpg/libwpg.h
/usr/lib64/libwpg-0.3.so.3
/usr/lib64/libwpg-0.3.so
Searching all installed packages for file collisions...
Press Ctrl-C to Stop
app-text/libwpg-0.3.0:0.2::gentoo
/usr/include/libwpg-0.3/libwpg/WPGraphics.h
/usr/include/libwpg-0.3/libwpg/libwpg.h
/usr/lib64/libwpg-0.3.so
/usr/lib64/libwpg-0.3.so.3
/usr/lib64/pkgconfig/libwpg-0.3.pc
Package 'app-text/libwpg-0.3.1' NOT merged due to file collisions. If
necessary, refer to your elog messages for the whole content of the
above message.
fixed by
# FEATURES="-collision-detect -protect-owned" emerge -1DNuv libwpg
... after which updating @world continues... (38 of 366 at the moment)...
If my fingers were crossed any harder, they'd dislocate.
storkk got a reaction from cardinal in First update in a while, slot conflicts ahoy. (python-related?)