03 APR 2026
David debugged: Caught prefetch_state='failed' masking a successful prefetch on Canvas candidates
David pushed back on the agent's claim that prefetch had succeeded, forcing the investigation to find that prefetch_state was overwritten by a downstream failure and not a prefetch failure.
When the agent reported that prefetch succeeded with attempted=6, completed=6, failed=0 but prefetch_state='failed', David refused to accept the framing:
I don't buy that. go and see what the primary files are that got prefetched and see if they were actually downloaded to s3
He then challenged the agent's incoherent explanation about page vs PDF file types:
yes and how is there meant to be a insert pdf pages requirement if the file type is a page? you said it failed due to not inserting the pdf pages and you even showed me what pages it was expecting. but then now you say oh no they were actually pages, not pdfs. that explanation isn't coherent
The investigation ultimately found that the prefetch_state field was overwritten by a downstream lecture-generation failure, not a prefetch failure — a misleading signal David's skepticism forced the agent to surface.