apt-get download package throws error 404 Not found

Question

I am trying to download ros package ros-kinetic-desktop using apt-get. I have set the sources.list and the authentication key as well. However, I am encountering an error that says:

Err:1 http://packages.ros.org/ros/ubuntu xenial/main arm64 ros-kinetic-desktop arm64 1.3.0-0xenial-20170303-020026-0800 404 Not Found [IP: 64.50.236.52 80]
W: Can't drop previleges for downloading as file 'home/sam/ros-kinetic-desktop_1.3.0-0xenial-20170303-020026-0800_arm64.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run(13: Permission)
E: Failed to fetch http://packages.ros.org/ros/ubuntu/pool/main/r/ros-kinetic-desktop/ros-kinetic-desktop_1.3.0-0xenial-20170303-020026-0800_arm64.deb 404 Not Found [IP: 64.50.236.52 80]

PS:sudo apt-get download ros-kinetic-desktop is the exact command I'm using.

Can someone please help me to resolve this. Thanks in advance.

EDIT: I am not supposed to use sudo apt-get update to update my entire cache ( especially the system packages) because the updated packages will crash my proprietary drivers. So, in order to just update the repositories I require, I manually added the ros repository to software and updates applet instead of using apt-get update. This way I am able to directly install the ros packages using install but unable to download them and manually install later.

Solution

Run

sudo apt-get update

(with sudo) to make sure the package list is up to date.

Then use just

apt-get download ros-kinetic-desktop

(without sudo)

If you use sudo then apt-get will download the file not as root but user _apt for security reasons. As _apt doesn't have write permission in home/sam/ you get this error.

Comments

[Mark Kirby]

Is their a difference between the package you want an ros-desktop package?

[George Udosen]

Is download a package name?

[samhitha]

@MarkKirby the package I am downloading is "ros-kinetic-desktop"

[samhitha]

@George download is the command that goes with apt-get, just like install but only downloads the package to a certain location and the package has to be manually installed later. ros-kinetic-desktop is my package.

[George Udosen]

Yes I remember now thanks for the refresher...

[Mark Kirby]

Use this syntax apt-get -d install ros-kinetic-desktop you will then find the deb at /var/cache/apt/archives AFAIK it won't install it.

[samhitha]

It seems to be installing as well. I tried simulating your command, it's working just like install.

[samhitha]

I edited my question to add why I cannot use sudo apt-get update. Can you please look into that and let me know if there's a work around?