This is a list of issues currently affecting international GNOME users. It’s not meant to be complete or comprehensive (most notably, bugs that are actively being worked on are missing), but rather a starting point for developers interested in helping. There is no particular order to the list.
Issues lacking manpower
#792180 — Background names are not used anywhere in GNOME, so translators are wasting time on them. Someone needs to rip i18n infrastructure from gnome-backgrounds wholesale.
#786766 — Context menu in Yelp is not translated. Needs someone to look into WebKitGTK integration.
#788381 — Notification asking for permission to share a screen is not translated. Probably easily fixable, but no one is taking care of Vino.
#1 — GNOME Builder has some strings from libdazzle that are not translatable. Developers are waiting for patches.
#780476 — Seahorse displays password descriptions from Epiphany in English. Other apps don’t have that problem.
#33 — Comboboxes in Tweaks are not translated.
#672675 — Theme names are not translated in five-or-more. — Fixed in 3.28.0 by Ruxandra Simion. Thank you!
#779413 — Dialogs asking for permission to access location are partly in English. Needs small API in GLib to show localized X-Geoclue-Reason from .desktop files. — Fixed in 3.27.4 by Florian Müllner and Philip Withnall. Thank you!
#708472 — Translated strings often don’t fit menus and dialogs and get cut. GNOME Shell (or rather its toolkit, St) uses pre-defined sizes and can’t elastically accommodate longer strings than the developer predicted.
Bugs outside GNOME that affect us
Issue #29 in PAM — GNOME displays strings asking for password on the login screen directly from PAM, and they are split, causing issues for many languages.
Issue #108887 in gettext — gettext extracts the Icon field from .desktop files to .po files. If a translator “translates” it, users in a particular language don’t get icons.