some random guy posted this bug https://bugs.kde.org/show_bug.cgi?id=251868 its a duplicate of https://bugs.kde.org/show_bug.cgi?id=244285 conclusion is: "Your poppler package is build with exceptions, we do not support that. Talk to your packager so that he does not build poppler with exceptions enabled." so maybe we should enforce exceptions being disabled on poppler when you are trying to install okular. Reproducible: Always
*** Bug 338241 has been marked as a duplicate of this bug. ***
Although I disagree with Albert (poppler developer) wrt exceptions as they expose actual memory bug and therefore that kde bug report is perferctly valid, requiring poppler without exception for okular can be done despite I don't like it at all. Bug is bug afterall. Btw 'exceptions' USE flag is disabled by default.
So be it then. Fixed in tree and overlay.