Re: [gentoo-dev] About using USE flags to pull in needed RDEPENDs being discouraged by devmanual

[Peter Stuge]

Pacho Ramos wrote:
> > I guess the point is that it is not really a dependency.
>
> No, it's a dependency only when you want ppp support working,

Logically, but not technically.

I like this separation; the package manager takes care of technical
requirements, and I get to take care of the logical requirements.


> > I dunno if a USE flag is much better? Both require the user to inform
> > herself in the same way ("when do I need USE=ppp for bluez" vs. "when
> > do I need to emerge ppp")
>
> It's much easier to widely set "ppp" USE in make.conf to be sure ppp
> support works for all things in my system that needing to rebuild
> affected package to see elog message telling me that I need to manually
> emerge some other package

My point is that when you know that you need ppp (and how could you
set USE=ppp otherwise) then it is about equally easy to emerge ppp
as it is to set USE=ppp.


> > > people end up with a lot of packages they needed to manually
> > > emerge some year but that they problem no longer need at all.
> >
> > Disk is pretty cheap. If the package is never being used and the user
> > doesn't care to remove it then the package doesn't do any harm IMO,
> > and as mentioned I think it's difficult for the package manager to
> > know what the user has installed on the system but no longer needs..
>
> What kind of argument is "disk is pretty cheap".

Please read the rest of what I wrote too. :)


> I still administrate a laptop with a 250GB of disk space, and that
> space cannot be as large if you have a lot of files at home.

My primary system had 8GB storage until a few years ago when flash
prices went down. I was motivated to keep my system clean. If one is
space constrained then I think one naturally pays more attention to
keeping world small. Disk is still cheap. If it is a problem for me
that I have unneeded packages installed, *then* I will start looking
at cleaning up. Until then, there's no problem.


> Also, you are missing that having unneeded packages in world file
> will also cause them to be updated on every system updated, with
> the time it takes for compile.

I'm not missing, but I'm saying that it is merely the effect of not
managing world very actively.

I think it's difficult to impossible for a package manager to
reliably determine logical requirements from what is a model
(USE flags) of technical requirements (link-time dependencies).


//Peter