Project kind-of worked but left a lot of messes for humans to clean up

A week ago, Cursor CEO Michael Truell celebrated what sounded like a remarkable event.

"We built a browser with GPT-5.2 in Cursor," he said in a social media post. "It ran uninterrupted for one week."

This browser, he said, consisted of three million lines of code across thousands of files. "The rendering engine is from-scratch in Rust with HTML parsing, CSS cascade, layout, text shaping, paint, and a custom JS VM.”

"It kind of works! It still has issues and is of course very far from WebKit/Chromium parity, but we were astonished that simple websites render quickly and largely correctly," he added.

Some developers managed to compile the code after some bug fixes. Others reported success after revisions to the build instructions.

But by and large, developers aren’t convinced Cursor has made a breakthrough.

Jason Gorman, managing director of Codemanship, a UK-based software development consultancy, argues it's proof that agentic AI scales to produce broken software.

...read more at theregister.com