Checker Concurrency Issues?
cs_checker_parallel_checks >= 1, there is a chance that the results recorded to the
problemstate log are not actually associated with the most
recent submission. A check should be added to make sure that the result we just computed is actually associated with the most recent submission before writing to the
I think this is what happened on 6.009's quiz 3 last term, where several students' submissions were left spinning.
Some work needs to be done here to reproduce the issue before we can really track down a fix.