Extract particular date snapshot from /var/db/portsnap?

[RW]

On Wed, 15 Jun 2011 12:44:30 +0400
Peter Vereshagin <peter at vereshagin.org> wrote:

> You can't take no for an answer, freebsd-questions!
> 2011/06/15 08:51:22 +0100 RW <rwmaillists at googlemail.com> => To
> freebsd-questions at freebsd.org :
> R> > - From what I see in /var/db/portsnap/files/ it keeps every file
> R> > it had ever downloaded: they all have different times.
> R> 
> R> It doesn't, it's a snapshot. The timestamps just reflect the last
> R> time each particular object was updated.
> 
> Hmm... looks like only a current ports state is kept in those tars:
> 
> $ tar
> -ztf /var/db/portsnap/files/12312e0e54a707a22613b0394a976c9d2044e98728b51c592d6e9a42c989300c.gz
> Makefile distinfo
> pkg-descr
> pkg-plist
> 
> such a single '.gz' extension was a false hint to me those are diffs.

It does download diffs, but it applies them to the snapshot, and then
discards them.