Re: Why does createrepo -C use ctime, not mtime?

On Wed, 7 Apr 2010, Robert Vogelgesang wrote:

> Hello developers,
>
> currently, I'm investigating an issue with "createrepo --update -C"
> when run by "cobbler reposync", and found in createrepo's source
> that the -C option is based on Python's os.path.getctime(), i. e. the
> time of the last status change on *nix hosts (ctime).
>
> As of version 2.0.3.1, "cobbler reposync" chown's and chmod's all
> files in a repo on each run, changing the ctime of all files in the
> repo; I think this is a bug in itself, but nonetheless I'd expect
> that mtime is used by createrepo when checking for changed files.
>
> createrepo's variable which holds the reference timestamp,
> self.mdtimestamp in class MetaDataConfig, seems to indicate that mtime
> should be, or even was historically used.  So, is there any special
> reason why this is based on ctime and not mtime?  I've searched
> createrepo's source, and http://createrepo.baseurl.org/, but found
> no answer.
>
> Can you shed some light on this, please?

You have to search pretty far back.

here is where the original -C behavior comes from:

http://lists.baseurl.org/pipermail/rpm-metadata/2006-July/000663.html

-sv