I'll submit a pull request to address this - but am just trying to get more information about whether I've missed something first.
I've written the following demo:
It shows a logback configuration with parent and child file references to the same file - and the parent append requests succeed and the child requests fail.
My question is: Is it a bug that logback doesn't warn that you've referred to the same file twice and just silently fails? (If so - we can fix this!)
Cheers
Julian