build-essential could not be installed on Kubuntu 20.04

Question

The following error is returned:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
 build-essential : Depends: libc6-dev but it is not going to be installed or
                            libc-dev
                   Depends: g++ (>= 4:9.2) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

I have tried sudo apt-get update and sudo apt install cmake but the error is the same.

The output of apt-cache policy build-essential libc6-dev libc6 libc-dev g++ cmake

build-essential:
  Installed: (none)
  Candidate: 12.8ubuntu1
  Version table:
     12.8ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
libc6-dev:
  Installed: (none)
  Candidate: 2.31-0ubuntu9
  Version table:
     2.31-0ubuntu9 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
libc6:
  Installed: 2.31-0ubuntu9.3
  Candidate: 2.31-0ubuntu9.3
  Version table:
 *** 2.31-0ubuntu9.3 100
        100 /var/lib/dpkg/status
     2.31-0ubuntu9 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
libc-dev:
  Installed: (none)
  Candidate: (none)
  Version table:
g++:
  Installed: (none)
  Candidate: 4:9.3.0-1ubuntu2
  Version table:
     4:9.3.0-1ubuntu2 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
cmake:
  Installed: 3.16.3-1ubuntu1
  Candidate: 3.16.3-1ubuntu1
  Version table:
 *** 3.16.3-1ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
        100 /var/lib/dpkg/status

Output of sudo apt update

Hit:1 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://ppa.launchpad.net/jonmagon/kdiskmark/ubuntu focal InRelease                                                                                    
Hit:3 http://dl.google.com/linux/chrome/deb stable InRelease                                                                                                
Ign:4 http://repo.vivaldi.com/stable/deb stable InRelease                                                                                                   
Hit:5 http://packages.microsoft.com/repos/code stable InRelease                                                                                   
Hit:6 http://apt.insync.io/ubuntu focal InRelease                                                                           
Hit:7 http://repo.vivaldi.com/stable/deb stable Release                                                                     
Hit:8 https://download.docker.com/linux/ubuntu focal InRelease                                        
Hit:9 https://download.sublimetext.com apt/stable/ InRelease

** grep ^deb -r /etc/apt/ --include=*.list **

said@~/Projects/Rust/hello_world$ grep ^deb -r /etc/apt/ --include=*.list
/etc/apt/sources.list:deb http://archive.ubuntu.com/ubuntu focal main universe restricted
/etc/apt/sources.list:deb-src http://archive.ubuntu.com/ubuntu focal main universe restricted #Added by software-properties
/etc/apt/sources.list.d/insync.list:deb http://apt.insync.io/ubuntu/ focal non-free contrib
/etc/apt/sources.list.d/vivaldi.list:deb http://repo.vivaldi.com/stable/deb/ stable main
/etc/apt/sources.list.d/google-chrome.list:deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main
/etc/apt/sources.list.d/jonmagon-ubuntu-kdiskmark-focal.list:deb http://ppa.launchpad.net/jonmagon/kdiskmark/ubuntu/ focal main
/etc/apt/sources.list.d/vscode.list:deb [arch=amd64,arm64,armhf] http://packages.microsoft.com/repos/code/ stable main
/etc/apt/sources.list.d/docker.list:deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu/ focal stable 
/etc/apt/sources.list.d/sublime-text.list:deb https://download.sublimetext.com/ apt/stable/

Update:

I had to reinstall Kubuntu 20.04. It was dirty installation in which formatting of / and /boot mount points had been occurred but /home left as it is and then creating the user with the same name of the previous installation to keep home settings intact.

I think this a major drawback of Debian based distros apt. I think that it is not found for Fedora dnf or OpenSuse yum. However, I think that the usage of apt install should be preceded by apt update and even the installation from *.deb files too.

"you have requested an impossible situation." The way to fix it is to uninstall the non-Ubuntu or wrong-version packages that are blocking. — user535733, May 04 '21 at 16:54
Does this answer your question? How do I restore the default repositories? — N0rbert, May 04 '21 at 16:57
@user535733 How could I know "non-Ubuntu or wrong-version packages that are blocking"? — SaidbakR, May 04 '21 at 17:14
Please add the output of apt-cache policy build-essential libc6-dev libc6 libc-dev g++ cmake. Also post full output of sudo apt update and grep ^deb -r /etc/apt/ --include=*.list (if long use pastebin). — N0rbert, May 04 '21 at 17:18
The version of libc6 that you have installed does not come from any repository on your system. You can tell this because the output of apt-policy for it is 100 /var/lib/dpkg/status So, at a guess, you installed something from a ppa and then removed the ppa, or you installed something from a downloaded file. The result is a broken packaging system. If you play those games, you have to be careful to completely back out of them, and that can be difficult. — Organic Marble, May 05 '21 at 01:46
Does this answer your question? Unable to correct problems, you have held broken packages — karel, May 05 '21 at 08:09
@karel, No for two reasons: 1, I already had to reinstall Kubuntu, 2, the top voted answer there is very old and there is no signed answer there. — SaidbakR, May 05 '21 at 18:31

build-essential could not be installed on Kubuntu 20.04

Update:

0 Answers0