A class project scraping data from a PC parts website to be used in a Prolog knowledge base.
Since this was for an Artificial Intelligence course, the point of the project was intended to be a Prolog knowledge base, using data pulled via a "third party API" from a parts picker website. However, Friday before the project was due (on Tuesday), the "third party API" suddenly stopped working. Turned out, the "API" wasn't so much an API as it was a web scraper for a site that lacked protections against being scraped. That scraper was dependent on the design of the site, so when the site redesign went live, the "API" broke. The scope of the project suddenly went from "let's collect some data to do interesting things with in Prolog" to learning how to write a web scraper and building several in three days.