Dpkg::Pre-Invoke {"mount -o remount,exec /tmp";};
DPkg::Post-Invoke {"mount -o remount,noexec /tmp";};
Quick hack as I use a noexec (nosuid, or whichever) /tmp on /etc/apt/apt.conf.d/50unattended-upgrades we need to tell to dpkg to change /tmp or some packages that need pre configuring will fail.