Re: [gentoo-user] emerge --depclean wants to remove required packages

[Bo Ørsted Andresen]

On Tuesday 27 February 2007 16:47:15 Alan McKinnon wrote:
> > > You have a bunch of packages that --depclean wants to remove. It
> > > looks like they should not be removed.
> >
> > A bit curious how you've reached that conclusion? Why shouldn't they?
>
> The OP said in his original mail
>
> "when I run emerge
> --depclean wants remove packages that would break dependencies"
>
> Presumably he knows his system well enough to know that the packages in
> question are necessary.
>
> I probably worded my statement wrongly as well. As written it implies
> that --depclean erroneously wants to remove things that should remain
> according to information in the ebuilds. I should have said --depclean
> wants to remove things that the OP would prefer to remain.

There are at least three reasons why you cannot rely on `equery depends` to 
tell you if a dependency which `emerge --depclean` is going to remove is 
required or not.

1) USE conditionals. This is adressed in latest ~arch gentoolkit (0.2.3) which 
prints the conditional. You still have to check the conditional yourself.

2) "|| ( bar baz )" blocks. `equery depends bar` and `equery depends baz` will 
print foo as depending on them. portage and hence `emerge --depclean` only 
requires one of them to satisfy the dep.

3) If the ebuild exists in the tree and has been modified since it was 
installed `emerge --depclean` will use the modified ebuild from the tree. 
`equery depend` will use the ebuild that was installed in /var/db/pkg.

In most if not all cases when `emerge --depclean` and `equery depends` 
disagree the former is correct (as of portage-2.1.1 at least (or 2.1?)). If 
you want to verify it with the latter you need to investigate the ebuild to 
see if any of the mentioned three cases apply...

-- 
Bo Andresen