Hey, I’ve been in this exact spot before—installing a package (like Cython) that crashes mid-install, and suddenly every apt or dpkg command throws errors. Don’t panic, let’s work through this step by step to get your system back on track.

1. Back Up & Reset Dpkg’s Corrupted State #

Half-installed packages often leave dpkg’s status files in a broken state. First, we’ll back up the current state (just in case) then reset it:

• Backup the critical dpkg files:

  sudo cp /var/lib/dpkg/status /var/lib/dpkg/status.bak
  sudo cp /var/lib/dpkg/available /var/lib/dpkg/available.bak
  

• Delete the corrupted state files:

  sudo rm /var/lib/dpkg/status
  sudo rm /var/lib/dpkg/available
  

• Regenerate clean state files:

  sudo dpkg --clear-avail
  sudo apt-get update
  

2. Force Remove Cython & Related Broken Packages #

Since the problem started with Cython, let’s target any partial or broken Cython packages:

• First, list all packages in a messed-up state (half-installed, unpacked, failed config):

  dpkg -l | grep -E '(half-installed|unpacked|failed-config)'
  

• If you see cython or python3-cython in the list, force remove them. Start with the gentler force flag, then escalate if needed:

  sudo dpkg --remove --force-remove-reinstreq cython python3-cython
  

  If that fails due to dependency errors, use the more aggressive force flag:

  sudo dpkg --remove --force-all cython python3-cython
  

3. Fix Broken Apt Sources List #

You mentioned cat /etc/apt/sources.list has issues—let’s repair that too:

• First, back up your current sources list:

  sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
  

• Now, replace it with a standard sources list for your Debian version. Find your version codename with lsb_release -c (e.g., bookworm for Debian 12, bullseye for 11). Here’s an example for Debian 12:

  echo "deb http://deb.debian.org/debian bookworm main contrib non-free non-free-firmware" | sudo tee /etc/apt/sources.list
  echo "deb http://deb.debian.org/debian bookworm-updates main contrib non-free non-free-firmware" | sudo tee -a /etc/apt/sources.list
  echo "deb http://security.debian.org/debian-security bookworm-security main contrib non-free non-free-firmware" | sudo tee -a /etc/apt/sources.list
  

  Swap bookworm with your actual codename if needed.

4. Run Standard Repair Commands #

Now let’s run the usual dpkg/apt repair commands to clean up any remaining issues:

• Reconfigure all unconfigured packages:

  sudo dpkg --configure -a
  

• Fix broken dependencies:

  sudo apt-get install -f
  

• Finally, update and upgrade to make sure everything is working:

  sudo apt-get update && sudo apt-get upgrade -y
  

Last Resort: Reinstall Dpkg Itself #

If none of the above works, your dpkg binary might be corrupted. Let’s reinstall it:

sudo apt-get download dpkg
sudo dpkg -i --force-all dpkg*.deb

Then repeat step 4 to finish the repair.

内容的提问来源于stack exchange，提问作者Aleksi Väisänen