port install efficiency issue

[Bryan Blackburn]

On Sat, Mar 21, 2009 at 11:58:33PM -0500, Ryan Schmidt said:
[...]
>
> There are valid reasons for wanting to rebuild a port that's already  
> installed. But it's probably reasonable to require the use of the -f flag 
> in those situations. And I believe that's what is supposed to be  
> implemented. But there appears to be a bug somewhere. I don't know if a 
> ticket is already filed about this.

I think port not only pays attention to epoch/version/revision but also the
timestamp of Portfile; when Portfile is newer than the install, even when
the versioning says it's already installed, it'll run again.  

Bryan