debconf: apt-extracttemplates failed: No such file or directory

I was running the command sudo apt install mongodb-org. And I got these errors.

E: Cannot get debconf version. Is debconf installed?
debconf: apt-extracttemplates failed: No such file or directory
Extracting templates from packages: 31%E: Cannot get debconf version. Is debconf installed?
debconf: apt-extracttemplates failed: No such file or directory
Extracting templates from packages: 63%E: Cannot get debconf version. Is debconf installed?
debconf: apt-extracttemplates failed: No such file or directory
Extracting templates from packages: 94%E: Cannot get debconf version. Is debconf installed?
debconf: apt-extracttemplates failed: No such file or directory
Extracting templates from packages: 100%
dpkg: error: unable to create new file '/var/lib/dpkg/info/format-new': No such
file or directory
E: Sub-process /usr/bin/dpkg returned an error code (2)

I am using Ubuntu 20.04.

Output of ls -ls /var/lib/dpkg/info/{,format-new} | head -n2

ls: cannot access '/var/lib/dpkg/info/': No such file or directory
ls: cannot access '/var/lib/dpkg/info/format-new': No such file or directory

Output of apt-cache policy debconf

debconf: Installed: (none) Candidate: 1.5.73 Version table: 1.5.73 500 500 focal/main amd64 Packages

1 Answer

You have severe damage of your system. Below is the possible way to fix this situation on low level:

# create missed dpkg info directory
sudo mkdir /var/lib/dpkg/info/
# create missed dpkg alternatives directory
sudo mkdir /var/lib/dpkg/alternatives
# recreate other directories as well
sudo mkdir /var/lib/dpkg/{parts,triggers,updates}
# update package lists
sudo apt-get update
# install missed debconf package
sudo apt-get install debconf
# reinstall all currently installed packages to correctly fill /var/lib/dpkg/info/
sudo apt-get install --reinstall $(dpkg -l | grep ^ii | awk '{print $2}')

And finally install whatever packages with commands like:

sudo apt-get dist-upgrade
sudo apt-get install mongodb-org