Would be useful if build logs (for example build/100/x86_64/log) for (failed and thus) deleted sub-tasks are kept until task is DONE (or rm'ed, or even archived). Advantages are numerous. This would valuable be addition to #42466.
Incorrect link to other bug, correct is #42552.
Just wanted to file the same bug but found it's already here. Advantage is people can analyze `log` while task is continued being worked on. Also, sometimes it's useful to compare build logs with older build attempt.
Really, we need complete information from all build iterations, including logs, tasks, repositories and much more. In my opinion, git repository or hard links will help to realize this function.