[plt-scheme] feature request for PLaneT

I'm not sure I understand the feature you're proposing. One thing I 
definitely _don't_ want is for PLaneT to ever change which package 
resolves a particular PLaneT require (in a particular file) without you 
explicitly telling it to do so --- if PLaneT upgrades your packages 
completely automatically and something goes wrong, it would be very 
difficult to figure out why your program worked yesterday but doesn't 
work today. (If you _want_ to change package's links, then you can use 
the PLaneT command-line tool or the utility functions provided by the 
planet collection to do that.)

Are you suggesting that a background thread check for minor revisions to 
installed packages, and when they become available offer to install them 
and relink packages that point to them (like, e.g., Windows Update)?

> A new version of a module that is downwards compatible will either 
> provide extra functionality,
> or provide bug fixes. It cannot by rule break the API syntax or semantics.

That's the rule, but there's no way for us to be sure that package 
authors follow it (they might even break it accidentally, e.g. by 
introducing new bugs). The fact that supposedly backwards-compatible 
upgrades might break things is a very important consideration, so we 
want to be very careful about features that upgrade things.

-jacob