Linux Tutorial: how to find and remove the old PPA repository on Ubuntu

Linux Tutorial: how to find and remove the old PPA repository on Ubuntu

Problem: I tried to synchronize the package index file again by running the apt-get update command, but the error "404 cannot be found" occurred, it seems that I cannot obtain the latest index from the third-party PPA repository previously added. How can I clear these broken and outdated PPA warehouses?

Err http://ppa.launchpad.net trusty/main amd64 Packages  404  Not FoundErr http://ppa.launchpad.net trusty/main i386 Packages  404  Not FoundW: Failed to fetch http://ppa.launchpad.net/finalterm/daily/Ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not FoundW: Failed to fetch http://ppa.launchpad.net/finalterm/daily/ubuntu/dists/trusty/main/binary-i386/Packages  404  Not FoundE: Some index files failed to download. They have been ignored, or old ones used instead.

When you try to update the APT package index, the "404 cannot be found" error always occurs after the version is updated. That is to say, after you upgrade your Ubuntu release, some third-party PPA repositories you added to the old version will no longer be supported by the new version. In this case, you can identify and clear the broken PPA repository as follows.

First, find the PPA that cause "404 cannot be found" error.

1. $ Sudo apt-get update | grep "Failed"

In this example, the PPA repository that Ubuntu Trusty no longer supports is "ppa: finalterm/daily ".

Remove the PPA repository.

1. $ Sudo add-apt-repository -- remove ppa: finalterm/daily

You have to repeat and repeat it to remove all the obsolete PPA repositories found above one by one.

After removing all obsolete PPA repositories, run the "apt-get update" command again to check whether they are successfully removed.

How to add the PPA software source to Ubuntu