Ubuntu 22.04 changed its default firefox package to come from a Snap instead of a traditional Debian package. Snaps apply some sandboxing to applications by default, which is probably what is interfering with opening these files in Firefox.
Changes like this are among the reasons I moved my systems from Kubuntu to Debian Bookworm, so I am probably not the best source for a solution, but there are a few possible directions to explore:
- I'm nearly certain there is a mechanism you can use to configure the sandboxing applied to the Firefox Snap. I don't know what that mechanism is for Snaps: with Flatpak, which has similar issues in this respect, you can use an application like Flatseal; CLI commands including
flatpak overrideandflatpak permission-set; or a Plasma 5.27 system settings page. - If there were a different way of doing things that would work better out-of-the-box with Snap- and/or Flatpak-based browsers, Racket could consider adopting it in the future, if it wouldn't be disruptive in the cases that already work well. At least we could document what permissions you need to set somewhere.
- Distribution packagers of Racket (including those who maintain the Snap and Flatpak packages of Racket) might be in a position to apply some integration settings in their packaging. Hypothetically, I could imagine a package of Racket that applied the needed sandbox settings when it was installed and removed them if it was uninstalled—but I could also imagine the complexity of this quickly getting unreasonable.