8e329d25fb
build-export is actually a low-level tool used by flatpak-builder. When using it directly, debug and locale extensions were not extracted as separate extensions (unless tweaking complicated command lines), ending up with a huge GIMP flatpak with the current procedure. Since flatpak 0.9.5, the option --export-only has been added to `flatpak-builder` so that the build and the export can be made in 2 separate steps while using the high level procedure. See: https://github.com/flatpak/flatpak/issues/824