That said, I suspect the actual problem is, like firefox, that the snap is saving the file to ‘/tmp’ within the context of the snap which is not ‘/tmp’ on the host so the pdf viewer is given the wrong and - in the case of xdg-open, I was thinking there might be something we can do here since we control xdg-open and it could in theory know the correct path on the host. Can you comment on if there a security denials in the journalctl logs at the time of the denial (if so, what are they)? If so it may be that thunderbird is not using xdg-open to open the file.
