`extern "C"` functions called from C code should guard against unwinding
As far as I can tell https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/blob/master/gstreamer/src/log.rs#L342-377 is called directly from GStreamer and then calls arbitrary Rust code. However it does not catch the unwinding that happens from the Rust end, therefore being (I believe) unsound especially with versions of Rust that don't mitigate this by introducing trampolines that abort in these kinds of situations.