Allowing PortGroups to bump port revision

[René J.V. Bertin]

On Sunday January 14 2018 00:01:34 Joshua Root wrote:

>portindex isn't slow, mportopen is. You have to evaluate the changed
>Portfiles before you can extract their info.

I didn't think disk I/O could be the limiting factor here. (It must be though during git pulls of the ports tree, judging from the size of the tree and the number of files it contains.)

It's orthogonal to the issue at hand, but maybe it would be worth the effort at some point to assess whether the indexing information that is really required cannot be extracted  reliably without parsing/running the entire Tcl programme that Portfile is. Or if the context cannot be simplified by shunting code that's of no interest for indexing. There don't appear to be alternative Tcl implementations like there are for Python, right?