librust-glib-sys-dev is declared Multi-Arch: same, but fails to
coinstall.

The file /usr/share/cargo/registry/glib-sys-0.20.9/src/lib.rs is shared
by librust-glib-sys-dev version 0.20.9-1 as present in trixie with
varying content.

The files
 * /usr/share/cargo/registry/glib-sys-0.22.6/GLib-2.0.gir
 * /usr/share/cargo/registry/glib-sys-0.22.6/src/lib.rs
are shared by librust-glib-sys-dev version 0.22.6-2 as present in
unstable and version 0.22.6-2 as present in unstable with varying
content.

Please ensure that shared files have bit-identical content across
architectures, move architecture-dependent files to
architecture-dependent paths or remove the Multi-Arch: same field.

Kind regards

Helmut Grohne