I previously tried to do-release-upgrade a VM running Ubuntu 14.04 server. The upgrade process kept halting to ask me what to do about config files that were not as expected, which I didn't know how to answer, because why would I. While spending several hours researching each file in turn to try to figure what to do with each one, the SSH connection (or something) dropped, and the upgrade halted as botched. I had to restore the VM from backup.
I'd like to try again. Is there any way to "dry run" do-release-upgrade to find out in advance what questions it's going to ask me so I can be prepared this time? There's nothing in the man page about a dry run, and web searches turn up nothing.
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