POTFILES.in needs updating
The translation page at https://l10n.gnome.org/module/gnome-terminal/ pointed out some files that need to be added or removed from po/POTFILES.in:
There are some missing files from POTFILES.in:
src/terminal-accel-dialog.cc
src/terminal-accel-dialog.ui
src/terminal-accel-row.cc
src/terminal-find-bar.ui
src/terminal-preferences-window.cc
src/terminal-preferences-window.ui
src/terminal-profile-editor.cc
src/terminal-profile-editor.ui
src/terminal-profile-row.cc
src/terminal-profile-row.ui
src/terminal-shortcut-editor.ui
src/terminal-window.ui
Following files are referenced in either POTFILES.in or POTFILES.skip, yet they don’t exist:
src/preferences.ui
src/profile-editor.cc
src/screen.ui
src/terminal-mdi-container.cc
src/terminal-menu-button.cc
src/terminal-menubar.ui.in
src/terminal-prefs.cc
src/terminal-tab-label.cc