Output of restic version

restic 0.16.4 compiled with go1.22.2 on linux/amd64

What backend/service did you use to store the repository?

Local

Problem description / Steps to reproduce

Backup errors printed to the console with --json have no error message. They look like:

{"message_type": "error", "error": {}, ...}

Expected behavior

An error message that could be displayed to a user should be in the JSON blob.

Do you have any idea what may have caused this?

Go's json encoder can't marshal error interfaces - restic should grab the error string with .Error()

I'm planning on fixing this - I have a patch. Just filing this for tracking purposes.