Bug#782507: libxrender1: i386/amd64 packages not co-installable

Interestingly, 'aptitude upgrade' installs both these packages w/o as much as a warning. (i have unattended-upgrades failing over this. Unfortunately, unattended-upgrades isn't e-mailing me on this failure as i would expect) Does this mean that 'aptitude' is not fully Multi-Arch aware/compliant?

Bug#953066: libpciaccess0: nVidia driver finds no devices, sddm dies with ABRT

Package: libpciaccess0 Version: 0.13.4-1+b2 Severity: important -- System Information: Debian Release: 9.12 APT prefers oldstable-updates APT policy: (500, 'oldstable-updates'), (500, 'oldstable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.19.0-0.bpo.6-amd64 (SM