In fact the problem is simple : libgweather-common.deb had not package the traductions (!!).
In debian sid, libgweather-common.deb (3.26.0-1) include (a part of) the trad files in /usr/share/locale. For example : /usr/share/locale/et/LC_MESSAGES/libgweather-3.0.mo /usr/share/locale/et/LC_MESSAGES/libgweather-locations.mo /usr/share/locale/eu/LC_MESSAGES/libgweather-3.0.mo /usr/share/locale/eu/LC_MESSAGES/libgweather-locations.mo /usr/share/locale/fr/LC_MESSAGES/libgweather-3.0.mo /usr/share/locale/fr/LC_MESSAGES/libgweather-locations.mo ....... See here the complet list of "normals" files : https://packages.debian.org/sid/all/libgweather-common/filelist. In Ubuntu 17.10 and 18.04, libgweather-common.deb has NOT these files. /usr/share/locale is not include. I picked the 2 files which interess me in libgweather-common.deb from sid : /usr/share/locale/fr/LC_MESSAGES/libgweather-3.0.mo /usr/share/locale/fr/LC_MESSAGES/libgweather-locations.mo and i copied them (in root) in the same directory on my disk. And GNOME-WEATHER just Work. In french. So please, rebuild libgweather-common.deb with /usr/share/locale/. Or directly use the sid version.... -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to libgweather in Ubuntu. https://bugs.launchpad.net/bugs/1704533 Title: French language locale missing : Gnome-Weather To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-weather/+bug/1704533/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs