# What to do about a crash in the #dtc animations language **URL:** \ **Category:** General\ **Created:** [June 27, 2025, 5:39pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810 "2025-06-27T17:39:09Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ddrake](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/ddrake/32/2353_2.png) [@ddrake](https://racket.discourse.group/u/ddrake)\ **Post date:** [June 27, 2025, 5:39pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810/1 "2025-06-27T17:39:09Z")
I'm reading [Don't Teach Coding Until You've Read This Book](https://forcoder.net/dont-teach-coding-until-read/) and working through some of the exercises there. Their code/languages are distributed with Dr. Racket, but the animations one crashes on my machine (Ubuntu 25.04). Here's one example: ```scheme #lang dtc/frames/animations (animation `(1 2 3)) ``` When I run that with F5, it prints "HI" and then after a moment, the entire Dr. Racket window goes poof! and disappears. In the terminal, I see: ```scheme (drracket:314334): exception raised by error display handler: internal error: attempt to deschedule the current thread in atomic mode; original exception raised: exception raised by exception handler: internal error: tried to deschedule a descheduled thread; original exception raised: internal error: attempt to deschedule the current thread in atomic mode internal error: tried to reschedule a scheduled thread internal error: terminated in atomic mode! ``` Any suggestions on how to fix that? It works on a Macbook, so it's something Linux- or Ubuntu-specific. Also, the book says its homepage is [https://www.dont-teach.com/coding](https://www.dont-teach.com/coding) -- but that site gives a 502 error. I've tried to contact the authors but have gotten no response. It would be great if the book's site was available, or at least had a page saying that it's been taken down. (FWIW, it does look like the book's code is available at [https://github.com/srfoster/dtc](https://github.com/srfoster/dtc).) ---
**Author:** ![benknoble](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/benknoble/32/16_2.png) [@benknoble](https://racket.discourse.group/u/benknoble)\ **Post date:** [June 27, 2025, 7:02pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810/2 "2025-06-27T19:02:29Z")
After `raco pkg install --auto dtc`, which btw generated this error ```scheme ts-kata-util/katas/rendering/pict.rkt:9:9: module: identifier already required at: translate in: pict also provided by: "../main.rkt" ``` in addition to lots of Scribble warnings, I ran the program. It printed `HI` to standard out, then after a long pause opened a window that displayed the digits 1, 2, 3, and then just a black screen. So perhaps running in DrRacket is the issue? ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/racket/original/1X/4e853055ae989ed00f69341cd98bee95980776c4.png) [@system](https://racket.discourse.group/u/system)\ **Post date:** [June 27, 2025, 8:04pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810/3 "2025-06-27T20:04:25Z")
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**Author:** ![ddrake](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/ddrake/32/2353_2.png) [@ddrake](https://racket.discourse.group/u/ddrake)\ **Post date:** [June 27, 2025, 8:05pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810/4 "2025-06-27T20:05:42Z")
Doesn't work for me if run as a script outside of DrRacket: see `https://gist.github.com/dandrake/72cbbf2bac0a410c34214493da8fa106` for the output. A bunch of invalid memory references, internal errors, and such. (Discourse isn't letting me post a link to gist.github, for some reason...) ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/racket/original/1X/4e853055ae989ed00f69341cd98bee95980776c4.png) [@system](https://racket.discourse.group/u/system)\ **Post date:** [June 27, 2025, 8:35pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810/5 "2025-06-27T20:35:55Z")
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**Author:** ![LiberalArtist](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/liberalartist/32/151_2.png) [@LiberalArtist](https://racket.discourse.group/u/LiberalArtist)\ **Post date:** [June 27, 2025, 10:00pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810/6 "2025-06-27T22:00:18Z")
> [@ddrake](#): > > Doesn't work for me if run as a script outside of DrRacket: see `https://gist.github.com/dandrake/72cbbf2bac0a410c34214493da8fa106` for the output. The source locations in that link include `/home/dan/.local/share/racket/8.12/`, which suggests that you are using Racket 8.12 from February 2024. Have you tried with the latest Racket 8.17? It's possible you are encountering a bug that has already been fixed. ---
**Author:** ![ddrake](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/ddrake/32/2353_2.png) [@ddrake](https://racket.discourse.group/u/ddrake)\ **Post date:** [June 28, 2025, 7:04pm UTC](https://racket.discourse.group/t/what-to-do-about-a-crash-in-the-dtc-animations-language/3810/7 "2025-06-28T19:04:25Z")
I get the same behavior with 8.17.