I think that this is how I got Extended running on 15.04:
1. sudo gedit /etc/apt/sources.list
2. find the line "deb
http://apt.puredata.info/releases vivid main"
3. replace with "deb
http://apt.puredata.info/releases raring main"
4. sudo apt-get update
5. sudo apt-get install pd-extended -y
This is not guaranteed though.
> Message: 5
> Date: Sat, 15 Aug 2015 14:10:40 -0700
> From: Forrest Curo <treegestalt@gmail.com>
> To: pd-list <pd-list@lists.iem.at>
> Subject: Re: [PD] [PD-announce] announcing Context, a modular >
> sequencer for PD
> Message-ID:
> <CAAn-EcySmx+e_fe8pukNeof2-s9eCMnQW5OtVwvR9H36eY_wRg@mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> for me (on ubuntu 15.04) fails at update:
> Fetched 1,157 kB in 1min 14s (15.5
> kB/s)
>
> W: Failed to fetch
> http://apt.puredata.info/releases/dists/vivid/main/binary-amd64/Packages
> 404 Not Found
>
> W: Failed to fetch
> http://apt.puredata.info/releases/dists/vivid/main/binary-i386/Packages
> 404 Not Found
>
> W: Failed to fetch
> http://ppa.launchpad.net/eighthave/pd-extended/ubuntu/dists/vivid/main/binary-amd64/Packages
> 404 Not Found
>
> W: Failed to fetch
> http://ppa.launchpad.net/eighthave/pd-extended/ubuntu/dists/vivid/main/binary-i386/Packages
> 404 Not Found
>
> E: Some index files failed to download. They have been ignored, or old ones
> used instead.
> -----------------
> and so, still 'failed to locate package.'
>
> Zexy is no doubt here somewhere, but to get iemguts?