I think this is the wrong direction (ie, backwards). Sacrificing current code to be compatible with old stuff feels wrong. Especially for really old, like rustc in debian bookworm.
bookworm has rustc-web (and a few related packages) which is regular rustc version 1.78, just renamed. It is regular bookworm, not backports. It has some packages disabled (compared to regular rust) and is a hack, but it exists and can be used for now (dunno if it is sufficient for qemu though). Also debian has backports mechanism, which also can be used for qemu - I can try back-porting regular rust (and llvm) to bookworm. I think this is a better way (at least a way forward) than trying to move backwards. But generally, what is the reason to support debian stable? I understand the CI thing, - we need a way to test stuff. For this, I'd say a better alternative would be to target debian testing (currently trixie), not debian stable. Thanks, /mjt
