Irrelevant "extraneous" packages present after fresh install

[Alexey]

I have installed LM 18.1 Cinnamon edition on my ASUS laptop with Intel Skylake i7 CPU. After that i installed updates and maybe a couple of packages. Then i decided to inspect the list of manually installed packages following this recipe:

  * http://askubuntu.com/a/492343/448153

I did this before on Ubuntu, and on a newly installed system the returned list would be empty, and after installing a few packages manually, only the names of these packages would be printed.

So i did (*)

    comm -23 <(aptitude search '~i !~M' -F '%p' | sed "s/ *$//" | sort -u) <(gzip -dc /var/log/installer/initial-status.gz | sed -n 's/^Package: //p' | sort -u)

To my surprise, i got a long list of package names, and almost all of them had ":i386" suffix. I have just tried this again (i have already installed quite a few new packages, but there should be no new "i386", i hope):

    aptitude search '~i !~M' -F '%p' | grep ':i386'

returned a list of 242 package names. Here is a sample from the middle:

> ...
> libdrm-amdgpu1:i386
> libdrm-intel1:i386
> libdrm-nouveau2:i386
> libdrm-radeon1:i386
> libdrm2:i386
> ...

(i do not even have nvidia or radeon).

I suppose there must be a bug in the installer. (Unless my installation sporadically malfunctioned -- does this still happen these days?)

As i mentioned, on Ubuntu, for comparison, after a fresh installation only the empty list is printed, and later the command (*) quite accurately prints only packages i have installed manually myself.