How can i get debugging information from a Darktable crash?

i can reliably crash Darktable by opening one set of photos. Other sets seem to work fine.

When I run Darktable from the command line, all I get in the output is “Segmentation Fault”. Is there a way to dump more details, ideally without having to run a special debug build? This is on Debian 11, Darktable 4.2.1

If this happens only on a set of photos, you probably have some corrupted ones.
To debug more darktable, just launch it with -d all option. You could list all possible options with -h option.

Are there photos using astro denoise?

Yes, I was trying the astro denoise module. I will try deleting the sidecar files and opening the set again.