Re: [gentoo-portage-dev] Dependency calculation turning on USE flags?

[Brian Dolbec]

On Sun, 2011-08-21 at 10:22 +1200, Kent Fredric wrote:
>
> On 21 August 2011 08:10, Matt Turner <mattst88@g.o> wrote:
>
>         See https://bugs.gentoo.org/372513
>
> ^ tldr version for everyone else.
>
> This is due to the || condition in virtual/fortran
>
> || ( sys-devel/gcc[fortran,openmp?]
> sys-devel/gcc-apple[fortran,openmp?] dev-lang/ifc dev-lang/ekopath-bin
> )
>
> Where gcc[fortran] takes precedence over ifc.
>
>
>
>         I wonder if there's some way we can manage this kind of
>         situation?
>         Perhaps portage could print alternative dependencies for
>         virtuals,
>         similar to the very helpful recent "The following keyword
>         changes are
>         necessary to proceed:" addition.
>
>
> This usecases specifics aside, I'd welcome some sort of way to show
> that an "or" condition is occurring somewhere in the tree, but it'd
> have to be opt-in, instead of opt-out, as the potential for being very
> noisy is great ( you'll get a lot of noise if you hit virtual/perl-*
> for instance ).
>
> And likewise, I'd love to have "some way" to produce some sort of
> graph for alternative merge trees that may work if you toggle some
> variable, but the amount of complexity to do this I'd imagine is quite
> large, and could easily be computationally expensive.
>
...

> Alternatively, you could let the user dictate what type of
> permutations to display/compute, ie:
>
>  use-flag based permutations, keyword based permutations, mask-based
> permutations, ||() conditional OR  based permutations,
> package-version/slot permutations etc.
>
> For "package version/slot" permutations, it would display every
> variation on package/slot ( ie: slots/versions that are not the
> "current" version ) that were installable, or installable with some
> permutation ( if the depth of permutation is large enough ), so that a
> user could see a path of installation they wanted and twist user masks
> to make it happen.
>
> Of course, this is all looking like harder and harder stuff to do
> ( programming is the gateway-drug for feature creep ) , but it would
> still be something nice to have on a theoretical magic computer that
> can do all computations in zero time.
>
> ¢¢
> --
> Kent
>


Well, for something now, you can emerge porthole and  look at the
Dependency view.  It will display all options and show the recommended
versions of the dep package (still needs some small tweaks to handle
slots correctly).  It is expandable (depth wise) until all deps are
satisfied.  The deps are also dbl-click able to pop up the dep in
another window so you can view/change it's settings, merge, unmerge,
etc..

And no it would not be suitable for portage, it is a guis based treeview
and for human use only ;)  

But it can show you the alternatives for such cases.  From there you can
decide how you want to set things for the merges.
-- 
Brian Dolbec <brian.dolbec@×××××.com>