I’m having trouble upgrading PSPP to GNOME 48. The build succeeds on x86_64 but it fails on ARM with the error “appstream-missing-screenshots: Catalogue file has no screenshots. Please check if screenshot URLs are reachable”. I can see that the build installs the screenshots in the same way in each flavor of the build. This happened similarly in two different builds.
The screenshot links are likely from gnu.org, which is not accessible inside github actions. Replace them with something else. You can host the screenshots in the flathub repo.
Anything other than that should work as long as it is not blocked inside GitHub actions runners. As I said, safest would be to put the images in the Flathub repo.