How to prevent ended job message from being cleared when using multiline prompt?

[lacygoill]

Consider this minimal prompt:

function fish_prompt
    printf '\n$ '
end

Written in /tmp/home/.config/fish/config.fish.

Start fish like this:

$ XDG_CONFIG_HOME=/tmp/home/.config fish

Finally, start a job:

$ sleep 1 &

When the job terminates, it writes a message on the terminal:

$ fish: Job 1, 'sleep 1 &' has ended

But most of the time, this message is automatically cleared (maybe 5 out of 6 times):

The issue disappears if the newline is removed from the prompt.

Is there a way to prevent the message from being cleared?

[zanchey]

Cute, I think this is a bug. #8817