[SOLVED] Failed to fetch cleishm/neo4j/ubuntu/dists/trusty/main/binary-amd64/Packages

Failed to fetch cleishm/neo4j/ubuntu/dists/trusty/main/binary-amd64/Packages

I am using Win10 Linux substyem which is

Description:    Ubuntu 14.04.5 LTS
Release:        14.04
Codename:       trusty

Then I tried to follow the libneo4j-client-dev installation guide for ubuntu

$ sudo add-apt-repository ppa:cleishm/neo4j
$ sudo apt-get update
$ sudo apt-get install neo4j-client libneo4j-client-dev

when executing the 'apt-get update', I found:

....
Err http://ppa.launchpad.net trusty/main amd64 Packages
  404  Not Found
....
W: Failed to fetch http://ppa.launchpad.net/cleishm/neo4j/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.

I once guessed it might be my system's fault, but after removing this ppa repository, this missing packages come back to appear again.

Has anyone seen the same problem and solved? Thanks for your attention in advance.

EDIT: More information The ppa information related is

/etc/apt/sources.list.d/cleishm-neo4j-trusty.list:deb http://ppa.launchpad.net/cleishm/neo4j/ubuntu trusty main

For comparison, the related ppa information on my ubuntu-virtualBox which libneo4j-client-dev is successfully installed is

/etc/apt/sources.list.d/cleishm-ubuntu-neo4j-xenial.list:deb http://ppa.launchpad.net/cleishm/neo4j/ubuntu xenial main

Solution

Launchpad was only publishing artifacts for the Xenial distribution. I've copied the packages to the Trusty distribution as well, so it might work now. Otherwise, I suggest upgrading to Xenial.