Have you test with that line gone from .treeinfo ? Does the key still need to exist ? I suspect were going to break other apps by completely removing the key
Over this way things still appeared to work fine with that particular line gone but honestly I haven't had time here to to exhaustive multiple tests beyond pulp sync against a repo with that line gone and some kickstart installs here with it gone.....
If you guys are already working through a similar issue in QA for 6.1 then let it be settled there and ignore the current mirrors for now - I can work around it in my environment here so it isn't a significant issue for me - just wanted to highlight it given that pointing to a file that doesn't exist is naturally bad behaviour from general perspective.....
Unfortunately I don't even have any upstream media here to confirm what that says given that boot.iso was removed with 6.0 and is a 5.X item...
I do wonder what other apps might be reading it and how they are behaving given the file doesn't exist.
James