vivid repo not found

[Glenn Holmer]

With a fresh install of Vivid alpha1, trying to run updates right after
the install gives:

http://extras.ubuntu.com/ubuntu/dists/vivid/main/source/Sources 404 not
found

Same thing for main/binary-amd64/Packages and main/binary-i386/Packages.

Is it a bug? There was a huge number of updates, all of which installed
successfully. After a reboot, the same error showed.

-- 
Glenn Holmer (Linux registered user #16682)
"After the vintage season came the aftermath -- and Cenbe."