An issue has been raised at the pacman-mirrors repo at Gitlab
Since I could not pinpoint the exact cause of it - but merely have made a ‘shot in the dark’ - I will ask anyone who runs pacman-mirrors in Hungarian language to report back if they can recreate this issue.
The user in question has the following language settings when the error occurs
LANG=hu_HU.UTF-8 LC_CTYPE="hu_HU.UTF-8" LC_NUMERIC="hu_HU.UTF-8" LC_TIME="hu_HU.UTF-8" LC_COLLATE="hu_HU.UTF-8" LC_MONETARY="hu_HU.UTF-8" LC_MESSAGES="hu_HU.UTF-8" LC_PAPER="hu_HU.UTF-8" LC_NAME="hu_HU.UTF-8" LC_ADDRESS="hu_HU.UTF-8" LC_TELEPHONE="hu_HU.UTF-8" LC_MEASUREMENT="hu_HU.UTF-8" LC_IDENTIFICATION="hu_HU.UTF-8" LC_ALL=
I would like to verify that the issue exist with the current version of pacman-mirrors in stable branch which is 4.10.1.
Secondly I would like to verify that the version currently in unstable fixes the issue. That version is v4.11.1dev.
Download here and when downloaded, from download folder, install with
sudo pacman -U pacman-mirrors-4.11.1dev-1-any.pkg.tar.xz
As the issue IMO is generic unicode issue - it should be present for anyone using a language which - like Hungarian - makes heavy use of accented characters.
The error should emerge immediately after the launch of pacman-mirrors - in the step where pacman-mirrors downloads the new files.