a way to specify that the port is source-only

[Jeremy Lavergne]

> I have some ports patched and being distributed through the 
> company's own portfile repo.  Let's say I have a custom
> "postgresql91" port with our custom patches.  Now, on many
> machines, instead of building it, it just downloads a pre-built
> version.  Can we add an option in Portfiles, like 
>     "source_only   yes" 
> or something like that?

What happens if you set archive_site_local in the Portfile? I think it'll get used as the place to fetch archives, so if you make it something bogus you'll kill archivefetch.