[conspire] tip: avoid downloading full isos when jigdo-lite fails (update to the 2009 tip)

[Tony Godshall]

[I wrote in 2009 and was quoted in linuxgazette]

> If you have an iso that fails checksum and a torrent is available,
> rtorrent is a pretty good way to fix it.
>
> cd /path/to/ubuntu910.iso && rtorrent http://url/for/ubuntu910.iso.torrent
>
> The reason torrent is good for this is that it checksums each block and
> fetches only the blocks required.

This also works when jigdo fails (i attempted to download
the ubuntu 12.04 alpha 2 isos via jigdo-lite to avoid re-downloading
the whole image and it gave me 404 errors on 30-some .deb files)

In this case I noted that the iso it was building was named
.iso.tmp, so I renamed that to .iso and then fired up deluge
on the .torrent

(Deluge is my latest favorite torrent client- the same competent
engine as rtorrent (libtorrent) but friendlier and hackable. Being
python-based means it's easy to instrument its interactions with
libtorrent or any other activity and learn how the infrastructure
works)

Tony