Reopened PR fails to run bors r+

A member of my team needed to make additional changes to some code that had been merged, so he re-opened the PR (that bors had successfully merged/closed) and made some changes. When it was approved, he ran bors r+, but got a response of "Already running a review". I checked the History in the bors dashboard, and it did not look like a review was being run.

He tried bors r- followed by bors r+, but got the same response from bors.

Is this behaviour expected?

It sort of is expected, yeah.

When using a regular Merge commit-based flow, GitHub won’t even let you do that, so bors wasn’t designed to handle it. It only happens because you’re using squash merge.

The error message could use improvement.