Re: Proper package relationships when a project depends on CBLAS

[Ghislain Vaillant <ghisvail@gmail.com>]

On 29/09/15 18:09, Felix Salfelder wrote:
> On Tue, Sep 29, 2015 at 05:49:50PM +0100, Ghislain Vaillant wrote:
> > > what is wrong with a builddep on libopenblas-dev|someotherblas-dev?
> > >
> > > do you want to discard the second option in case the first is available
> > > (don't know how to do that)?
> >
> > If I use say libopenblas-dev | libatlas-dev, then the generated
> > binary package will have a Depends field with either
> > libopenblas.so.X or libatlas.so.X.
>
> i assume this dependency is generated by dh_shlibdeps and your control
> file lists ${shlibs:Depends} in the list of binary package dependencies.
> for sure you can exchange that for whatever you please, e.g.
> libopenblas.so.X | libatlas.so.X
>
> > Instead, I should probably have
> > libblas.so.X which can be updated via update-alternatives to any of
> > these implementations.
>
> if there is a virtual package that depends on one of the above, then
> sure, depend on that one.

Now I understand. I have replaced this dependency with:
BuildDepends: libblas-dev | libblas.so

Whereby libblas.so can be provided by libopenblas-dev or libatlas-dev.

Then the binary package gets the following dependency:
Depends: libblas.so.3

Which may be provided by libopenblas, libatlas or libblas, via 
update-alternatives.

> > Or should I actually care?
>
> this is up to you. (but yes, sounds fun).

One learns something everyday :-)

Many thanks Felix for your pointers.

Ghis