108K views · Feb 21, 2023 · 14:06 · 5 HN recommenders · 7 mentions · discussed 2023–2026
Allan Blomquist demonstrates the internal programming and debugging tools Tomorrow Corporation uses to make games, including live modification of a running game and time-travel debugging.
Why Hacker News points people here: Held up in debugger and tooling threads as an amazing ideal of a tight feedback loop and what debugging could be.
“this demo has got to be the closest thing to the perfect debugger I've ever seen”HN comment, 2023
“this demo has got to be the closest thing to the perfect debugger I've ever seen”
Closest thing to a perfect debugger
> I should mention that the perfect debugger doesn’t exist It may not exist, but this demo has got to be the closest thing to the perfect debugger I've ever seen: this video
“Allan Blomquist's tooling demo they mention is incredible, go watch it”
Tooling demo showing tight developer feedback loop
Allan Blomquist's tooling demo they mention is incredible, go watch it: this video Really sells the value of having a tight developer feedback loop: it shows hot reloading for code and graphics, a reversible debugger, live profiling with flame graphs, a data inspector with data breakpoints, time travel inspection with a scrub bar, session sharing and replay with the same scrub bar and direct links from the call stack to a breakpoint, and more. Above the many niggles they had with Rust itself, this greatly helps me understand why Rust left them wanting more from their working environment. They say they've switched back to Unity with link to try to capture some of that, and now I see why. (It's a shame that hot reloading tooling in Rust wasn't ready for them yet, but I see why they've moved on instead of waiting/contributing.)
“this demo represents an amazing ideal of what debugging could be”
Ideal of what debugging could be
This is a legitimate question but this was clearly generated using an LLM. To add something constructive, this demo represents an amazing ideal of what debugging could be: this video
“Check out this wild video[1] of someone modifying and debugging a game in real time.”
Live modification and debugging of a game
A whole world of creative opportunities open up when the toolchain and related debugging tools don't suck. Check out this wild video[1] of someone modifying and debugging a game in real time. [1]: this video
“Very impressive, worth a watch.”
Demo of time-travel debugging
Yes, I'm a big fan of Bret Victor's work. I share his Inventing on Principle talk on a near yearly basis. I've seen light table years ago and thought it looked really neat, but I haven't looked into it much as it wasn't directly applicable to my environments. But, probably worth a look for ideas. On the topic of time-travel debugging, have you seen the demo: this video (Tomorrow Corporation Tech Demo) Very impressive, worth a watch.
Lisp-image-like game dev environment with time travel debugging
He mentions Common Lisp as something he did a game in, and you can see the link he praises this video as basically a very well-developed Lisp image approach with timetravel debugging etc aimed at game dev. So the implicit comparison to Lisps is sort of a big undercurrent to this whole article.
“Has neat features like time-travelling debugging and instant hot-reloading for code and assets.”
Custom stack with time-travel debugging and hot reload
Reminds me of the Tomorrow Corporation (developer of World of Goo) tech demo: this video Their entire stack is custom (language, compiler, IDE, build system, engine). Has neat features like time-travelling debugging and instant hot-reloading for code and assets.
