So basically, this is a system which would replace all of the random places that things can go in Boot? Or rather, be an interface to them all?
Like I said before, I really don't mind the idea. But I do worry about applications becoming less 'atomic'. Having had to install programs on a PC, and know that it might add or modify things over the whole directory tree - after which things would never work properly again. Thus far, it hasn't been a problem on the RPC.
What does GCC do which is so special? I mean, I know its a compiler, and believe it to require a lot of configuration...
"But how do you know you have the latest version, or where to get the latest from?"
How could the package manager tell you this? Check the website for you then perpetually bug you to update, or update without you knowing? What if I want to keep the version I've got?
"How [can you be sure] you have all the parts of the application?"
If it doesn't work, thats a clue (I'm sure you know what happens at the moment; I don't see how a package manager could improve matters beyond this. If it can't find module X then having an installer inform you is not really any different to having the Run file tell you.)
"How can you be sure you have all the bits it relies upon?"
Because if it doesn't, it should tell you and tell you how to get them. (Isn't that the same question as above, basically?)
"How do you know to change the config file if its format has changed?"
Um, dunno. How would the package manager do that? A custom updater could of course supply a tool to do it if necessary.
"None of these questions can be answered reliably if done manually, and often are very frustrating even for seasoned users."
As you can see, I really am in the dark as to how a package manager would help matters. Please don't think I'm being sarcastic, I just don't 'get' it.
If the answer to this series of your questions is really just that it saves programming effort, and standardises the amount of information given for errors that is fine, that is a noble effort, but you seem to be promising that it will fix problems and I can't see how it will really make any difference for those to the end-user.