[Borgbackup] borg outputs "Failed to securely erase old repository config file" twice in borg check

[Felix Schwarz]

Hi *,

recently there was a change on our storage platform which hosts our borg repos. 
Now the remote filesystem does not support hardlinks anymore.

So every "borg check" outputs some lines like this:

# borg check --repository-only <repo>
Remote: Failed to securely erase old repository config file (hardlinks not 
supported). Old repokey data, if any, might persist on physical storage.
Remote: Failed to securely erase old repository config file (hardlinks not 
supported). Old repokey data, if any, might persist on physical storage.

and that is really annoying because - as you can guess - this triggers an email 
if the "check" job is run by cron.

After reading the discussion in various github issues (especially 
https://github.com/borgbackup/borg/issues/3591#issuecomment-363362442) I think I 
have a rough idea why borg outputs the warning but I think it is not relevant in 
our case (not using repokeys).

# rpm -q borgbackup
borgbackup-1.1.18-2.el7.x86_64


Questions:

- Is there a way silence the warning?
- Why does "borg check" want to rewrite the config?

Thank you for your time,
Felix