Thanks for checking and getting back to us. Our engineers are still looking into this, and we’ve been able to reproduce it inconsistently. Our working theory right now is that this is a race condition between two Github hooks, one for a push and one for a PR commit. We’ve been able to reproduce this using a commit from the Github PR web UI, so it’s not a simple matter of “create a PR then push to it”.
For now, rebuilding is the only suggestion I have while our engineers look into this further.