Comment by lulouie

yep, is because Arch (basically because qt5 upgrade...), and with the issue on it: https://bugs.archlinux.org/task/63051

$ calibre

Fatal Python error: PyQt5.QtCore: Unable to embed qt.conf

[1] 13321 abort (core dumped) calibre

At that moment, I didn't have time to workaround on it :(