Due to being a dumb dumb, I've had an unencrypted repo for YEARS because my key had an empty password.

I only found out about it because I was restoring from a new machine and this message came up:

Warning: Attempting to access a previously unknown unencrypted repository!

Two problems:

1. This message only shows once on a given machine.
2. It doesn't say which of two reasons it's "unencrypted". I did a borg info and saw that my repo was encrypted, so I almost shrugged it off as a bug it until a redditor mentioned I might have an empty passphrase.

Better would be for this sort of behavior, every access.

$ borg info server:repo
Warning: Repo is unencrypted (encryption=none set)

or

$ borg info server:repo
Warning: Repo is unencrypted (empty key passphrase)

People with a known unencrypted repo can set an env var to shut it up.

I know it's not terribly impressive that I let this go unnoticed, but it was silent and there will be other people hanging out with me on this part of the bell curve :)