How to fix subprocess new post-installation script returned error exit status 1 in APT

Run this command to fix any packages that are installed but not fully configured:

sudo dpkg --configure -a

This tells dpkg to configure all packages that have pending configuration. In many cases, this resolves the issue automatically.

If the above doesn't work, repair any broken dependencies:

sudo apt install -f

The -f flag stands for --fix-broken and will attempt to install missing packages or upgrade packages to fix dependency issues.

Verify you have sufficient disk space, especially in the /boot and / partitions:

df -h

If any partition shows 100% or close to it (especially /boot), you'll need to free up space before the package can complete installation. Remove old kernel images or unnecessary files.

Look at the full error message to identify which specific package is causing the issue. The error will typically show the package name. You can check the dpkg log for more details:

cat /var/log/dpkg.log | tail -20

This shows recent dpkg operations and may reveal what failed.

Once you've identified the package, try removing and reinstalling it:

sudo apt remove <package-name>
sudo apt install <package-name>

Replace <package-name> with the actual package name. This forces a clean installation from scratch.

If the error mentions DKMS, kernel modules, or drivers (like nvidia, displaylink, evdi), try rebuilding the DKMS modules:

sudo dkms autoinstall

You can check which DKMS modules are installed:

dkms status

If a specific module is failing, you can check its build log:

cat /var/lib/dkms/<module-name>/<version>/build/make.log

Clean the apt cache and refresh package lists:

sudo apt clean
sudo apt update

Then try installing packages again. This clears any corrupted cache that might be interfering.

If all else fails, you can temporarily bypass the problematic post-installation script. This is a last resort:

ls /var/lib/dpkg/info/ | grep <package-name>

Locate the .postinst file for your package, then move it:

sudo mv /var/lib/dpkg/info/<package-name>.postinst /tmp/<package-name>.postinst.bak

Now try reconfiguring:

sudo dpkg --configure -a

WARNING: This bypasses important configuration steps. Only use if the package is non-critical and you understand the consequences.