Greetings @Mowlwurf,
I think I have a theory of what might be wrong. I notice the recipe for librsvg uses rust to build and compile. Our remote-access client (rac) in Torizon also uses rust. However, it required a newer version of rust then what was available in openembedded-core. Therefore we back-ported a newer version of rust in our meta-layer: meta-toradex-torizon/recipes-devtools/rust at kirkstone-6.x.y · torizon/meta-toradex-torizon · GitHub
It might be the case that librsvg here does not work with the newer version of rust that we back-ported. This would match your observations because we backported the newer version of rust for the 6.3 release.
You could try removing the backport, or setting the rust version to the version available in openembedded-core kirkstone: meta-toradex-torizon/conf/distro/include/torizon.inc at kirkstone-6.x.y · torizon/meta-toradex-torizon · GitHub
But, then our remote-access client would fail to build most likely. Not sure if you care about this. Another idea is that you could try back-porting a newer version of libsrvg that is more compatible with the version of rust that we backported.
Best Regards,
Jeremias