Adding a local directory for distfile fetching

[Vincent Habchi]

Hi Ryan,

> I have multiple MacPorts prefixes on my machines. I delete their var/macports/distfiles directories and replace them with a symlink to a central location, such as /Volumes/Data/macports/distfiles if I have a separate partition or $HOME/macports/distfiles if I don't.
> 
> On some of my machines, I run a web server and expose this directory. On other machines, I then edit mirror_sites.tcl and add the local server addresses to the macports_distfiles section, so that if one machine doesn't have a distfile, it tries to fetch it from other local machines before hitting the Internet.

If I figure out your answer correctly, there is no way to directly add a file URL to the macports_distfiles section. The idea was that if the removable disk is connected and has the corresponding distfile, then we extract directly from it, else we fetch on the Internet.

Vincent