Why are there only sometimes images in rawhide?

[Bruno Wolff III]

On Mon, Feb 11, 2008 at 19:58:15 -0500,
  Jon Stanley <jonstanley at gmail.com> wrote:
> On Feb 11, 2008 7:46 PM, Bruno Wolff III <bruno at wolff.to> wrote:
> 
> > OK, thank makes sense. The next time they show up, I think I'll make a
> > separate copy of the images. Otherwise when I resync my local copy they go
> > away, which means falling back to the alpha rescue iso, which may not have
> > some fixes in it.
> 
> I don't use --delete on my local copy by default - so I always have an
> image to install from.  Obviously won't work if disk a concern,
> though.

It is now, but once I get my new machine working it won't be.
Also I had been doing this for updates, where generally deleting hasn't
been a problem. I am seeing that rawhide is a different beast and keeping
old stuff around is more likely to be useful. The mirrors can also be out
of sync and I have seem some thrrashing, where I was hoping to pick up
some missing stuff and instead had the partial list of updates I had
gotten already deleted instead.