I experienced a packaging issue today and decided to subject our "Update Issues" message to the wife test by asking my wife to figure out what to do. The moment the message appeared, she looked at me like I was made of killer bees.
The problem here is that the message still shoves technical details in the user's face, which can be a scary wall of text that will prevent them from reading it or anything beneath it--including the "Please report this issue to the packagers of your distribution" text.
This commit turns it into a two-stage message: by default the user will see a friendly error message that advises them to simply try again later (which often does fix transient packaging issues), and if they want, they can show the technical details and report it to their distro. When they do so, the technical error message is shown in a TextArea that you can easily copy text from, and only then is the "Report this issue" button shown.
This should improve the UX for the "your distro is shipping broken packages" case.