There is a bug where internal pages are getting evicted despite having child pages that are still on pre-fetch queue. This bug has been observed with special operations which don't go through the normal eviction flow and forcibly remove contents from the cache. As a result, we skip the __evict_child_check function which prevents internal pages from being evicted if they have child pages on the pre-fetch queue, and hit an assertion that a ref on the pre-fetch queue does not have the WT_REF_FLAG_PREFETCH set as the ref has been freed accidentally.

WT_ASSERT_ALWAYS(session, F_ISSET(pe->ref, WT_REF_FLAG_PREFETCH),
          "Any ref on the pre-fetch queue needs to have the pre-fetch flag set");