Re: [gentoo-user] virtual eselect - how to

[Mick]

On Wednesday, 26 June 2019 14:05:27 BST Helmut Jarausch wrote:
> Hi,
> what is the relationship of a virtual package and eselect.
> E.g.
> I have installed openblas but 'eselect blas list' doesn't know about
> this.

I assume it doesn't know about it because there is no eselect module for blas.


> I have even modified  virtual/blas to include openblas.

Virtual packages are there to make sure at least one of alternative packages 
satisfying dependency requirements will be installed.  So, some package you 
installed requires a database.  A virtual/<database_required> will be 
installed to make sure at least one of the database packages to satisfy the 
dependency requirement is installed.


> How does eselect get the list of alternatives?
>
> Many thanks for a hint,
> Helmut

My understanding is package devs will have to create a corresponding eselect 
module, in order manage the symlinks for the various versions of said package 
which are available in the tree at any time.

In absence of an eselect module, you can create any desired symlinks yourself.  
I often forget there are so many eselect modules these days.  I found myself 
using rm and 'ln -s' to change profiles, only to recall eselect does this in a 
single incantation.

-- 
Regards,

Mick