Bugfix release 4.11.2
Following the thirdparty succesful verification of the bug and the working fix I am pleased to announce that official release for the fix of this bug.
The error existed because the gettext call in the i18n tranlation module did not ask for unicode messages which would generate the UnicodeEncodeError when the returned text did not fall into the ASCII character range.
The package will eventually reach stable branch but if you do experience this bug then download the new package from unstable and do a local install from your download folder.
sudo pacman -U pacman-mirrors-4.11.2-1-any.pkg.tar.xz
Thank you for your patience - and have a great day.