I just tried adding the steam repo to 16.04 (I had steam from 14.04, and at another computer I downloaded the .deb file), and I get the same issue. Additionally, I see:

E: Failed to fetch http://repo.steampowered.com/steam/dists/xenial/main/binary-amd64/Packages  404  Not Found [IP: 24.200.120.16 80]
E: Failed to fetch http://repo.steampowered.com/steam/dists/xenial/main/binary-i386/Packages  404  Not Found [IP: 24.200.120.16 80]

It seems like a distribution upgrade changed the target distribution for our repository from 'precise' to 'xenial' in your APT sources. If you use the 'precise' target you should be able to install our package without issues.

We are on xenial! But now that you have found the issue, then hopefully fixing it on your side is just a matter of configuration.

We use the precise folder for all versions post-12.04, so 'precise' is what you need to target for our repository even if you are running 16.04.

People who know nothing about ubuntu or steam just want to play steam
games. I don't think asking everyone to edit config files will work out
On 7 May 2016 10:44 a.m., "Pierre-Loup A. Griffais" <
[email protected]> wrote:

Closed #4436
https://github.com/ValveSoftware/steam-for-linux/issues/4436.

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The bug is with the Ubuntu distribution upgrade script mistakenly editing third-party software sources.

Who do we contact in order to get this fixed
On 7 May 2016 1:16 p.m., "Pierre-Loup A. Griffais" [email protected]
wrote:

The bug is with the Ubuntu distribution upgrade script mistakenly editing
third-party software sources.

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I'd expect ubuntu's bug tracker would be a sensible place to continue pursuing this, but I suspect there's more legitimate scenarios where this behavior is for the greater good.

I believe @Plagman is incorrect. The Steam repository is broken if it doesn't follow the convention of accepting the currently running client O/S as a folder. All they need to do is add sym links, for instance, to fix it.

I agree with @tomchiverton. It makes more sense for distribution upgrade to set the correct distribution for third party repositories. If it didn't, everybody had to manually update all their third party repositories to the correct distribution, which is certainly a bigger hassle for the users.

A symlink is likely all it takes, requiring no extra disk space. The problem is a lot simpler to fix on Steam side than on users'.

@Plagman, I think the way Google Chrome handles this would also work well for you. Rather than using the distro name, they use stable.

See step 2 here.

@Plagman any chance you could reopen this bug, and make it a TODO and your guys' side to implement https://github.com/ValveSoftware/steam-for-linux/issues/4436#issuecomment-222023703 ?

Thanks much

A stable suite is now available (it has the same content as precise). Version 1.0.0.64 of the steam-launcher package, currently in beta, changes steam.list for new installations to have this content:

deb [arch=amd64,i386] https://repo.steampowered.com/steam/ stable steam
deb-src [arch=amd64,i386] https://repo.steampowered.com/steam/ stable steam

# Uncomment these lines to try the beta version of the Steam launcher
#deb [arch=amd64,i386] https://repo.steampowered.com/steam/ beta steam
#deb-src [arch=amd64,i386] https://repo.steampowered.com/steam/ beta steam

steam.list is managed as a dpkg conffile, so for existing installations, whether it is replaced or kept as-is will depend on your apt/dpkg configuration and whether you have modified it locally.