how to add apt-utils in aptcache so cowbuilder/pbuilder can use it?

I was running cowbuilder --update and got the following - $ sudo cowbuilder --update [sudo] password for shirish: I: Copying COW directory I: forking: rm -rf /var/cache/pbuilder/build/cow.12496 I: forking: cp -al /var/cache/pbuilder/sid-amd64/base.cow /var/cache/pbuilder/build/cow.12496 I: removed stale ilistfile /var/cache/pbuilder/build/cow.12496/.ilist I: Invoking pbuilder I: forking: pbuilder update --buildplace /var/cache/pbuilder/build/cow.12496 --mirror http://deb.debian.org/debian/ --distribution sid --no-targz --internal-chrootexec 'chroot /var/cache/pbuilder/build/cow.12496 cow-shell' I: Running in no-targz mode I: Current time: Sun Sep 2 01:16:22 IST 2018 I: pbuilder-time-stamp: 1535831182 I: copying local configuration W: --override-config is not set; not updating apt.conf Read the manpage for details. I: mounting /proc filesystem I: mounting /sys filesystem I: creating /{dev,run}/shm I: mounting /dev/pts filesystem I: redirecting /dev/ptmx to /dev/pts/ptmx I: policy-rc.d already exists I: Refreshing the base.tgz I: upgrading packages Get:1 http://cdn-fastly.deb.debian.org/debian sid InRelease [233 kB] Get:2 http://cdn-fastly.deb.debian.org/debian sid/main amd64 Packages.diff/Index [27.9 kB] Get:3 http://cdn-fastly.deb.debian.org/debian sid/main amd64 Packages 2018-09-01-1408.47.pdiff [11.0 kB] Get:3 http://cdn-fastly.deb.debian.org/debian sid/main amd64 Packages 2018-09-01-1408.47.pdiff [11.0 kB] Fetched 272 kB in 3s (97.6 kB/s) Reading package lists... I: Obtaining the cached apt archive contents Reading package lists... Building dependency tree... Reading state information... Calculating upgrade... The following packages will be upgraded: libidn2-0 1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 76.4 kB of archives. After this operation, 120 kB of additional disk space will be used. Get:1 http://cdn-fastly.deb.debian.org/debian sid/main amd64 libidn2-0 amd64 2.0.5-1 [76.4 kB] Fetched 76.4 kB in 1s (79.8 kB/s) debconf: delaying package configuration, since apt-utils is not installed (Reading database ... 11986 files and directories currently installed.) Preparing to unpack .../libidn2-0_2.0.5-1_amd64.deb ... Unpacking libidn2-0:amd64 (2.0.5-1) over (2.0.4-2.2) ... Setting up libidn2-0:amd64 (2.0.5-1) ... Processing triggers for libc-bin (2.27-5) ... Reading package lists... Building dependency tree... Reading state information... 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Reading package lists... Building dependency tree... Reading state information... aptitude is already the newest version (0.8.10-9). build-essential is already the newest version (12.5). dpkg-dev is already the newest version (1.19.0.5). 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. I: Copying back the cached apt archive contents I: new cache content 'libidn2-0_2.0.5-1_amd64.deb' added I: unmounting dev/ptmx filesystem I: unmounting dev/pts filesystem I: unmounting dev/shm filesystem I: unmounting proc filesystem I: unmounting sys filesystem I: removing cowbuilder working copy I: Moving work directory [/var/cache/pbuilder/build/cow.12496] to final location [/var/cache/pbuilder/sid-amd64/base.cow] and cleaning up old copy I: forking: rm -rf /var/cache/pbuilder/build/cow.12496-12496-tmp Now in /var/cache/pbuilder I get the following directories - /var/cache/pbuilder$ ls aptcache build result sid-amd64 Now from little I understand aptcache has the .deb packages that may be needed, build is where a package is being built, result is when there are successfully built packages and sid-amd64 where the base.cow or the minimal Debian distribution which needs those packages for package building are there. IIUC, then both aptcache and base.cow will fatten over time as new packages are being built. Am I correct in this understanding ? If yes, how do I go about adding apt-utils in aptcache as well as the base.cow ? See this line from the action shared before - debconf: delaying package configuration, since apt-utils is not installed. Update - 02/09/18 - I tried the following - $ sudo pbuilder --autocleanaptcache pbuilder - a personal builder Copyright 2001-2007 Junichi Uekawa Distributed under GNU Public License version 2 or later pbuilder [operation] [pbuilder-options] pdebuild [pdebuild-options] -- [pbuilder-options] ........ For some reason it seems the command does not work, either I spelled it wrongly or it needs the explicit path for the command to work. Before that I did try $cowbuilder ----autocleanaptcache but even that didn't get anything. At the end I had to go with - $ sudo pbuilder clean I: Cleaning [/var/cache/pbuilder/build] I: removing directory /var/cache/pbuilder/build and its subdirectories I: Cleaning [/var/cache/pbuilder/aptcache/] shirish@debian:~$ cd /var/cache/pbuilder/aptcache/