Actually, sorry, that's wrong (but it's still an apt bug I think). Looking at the log, this appears to be a multiarch handling issue. The second mention of libdrm-nouveau2 there I think is actually supposed to be referring to libdrm-nouveau2:i386, but that hasn't been unpacked and it isn't referring to it by its architecture-qualified name. These two things may be connected.
Actually, sorry, that's wrong (but it's still an apt bug I think). Looking at the log, this appears to be a multiarch handling issue. The second mention of libdrm-nouveau2 there I think is actually supposed to be referring to libdrm- nouveau2: i386, but that hasn't been unpacked and it isn't referring to it by its architecture- qualified name. These two things may be connected.