miss-islington is an awesome bot! It makes fixing bugs in multiple versions much simpler. You need just accept automatically created backporting PRs.
But there is a downside. miss-islington makes the life so easier, that sometimes you forgot about not finished backports. miss-islington can fail to backport some changes for different reasons. Currently on GitHub there are tens merged PRs labeled for backporting, but backports were not finished. Please take attention if your PRs in one of the following lists: