The Oct 21 release version of problemtools seems to have severe performance degradation from the April 22 release, on slow-running scripts.

Concrete examples include the ascendingphoto problem from NWERC 2017 (e.g. case 07-big.in went from 4.7 to 6.0 seconds) even though b281d3f, added between the two versions, claims to improve performance on that specific set.

As an extreme example, I found one script that took ~5 minutes to run on the April 22 release, and more than 3 hours (after which I decided to stop waiting) to run on the Oct 21 release.