[petsc-dev] pkgconfig

[Barry Smith]

On Nov 1, 2012, at 7:12 PM, Matthew Knepley <knepley at gmail.com> wrote:

> On Thu, Nov 1, 2012 at 7:01 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> 
>    Matt,
> 
>    There are two things. (1) Generating one for a PETSc install that others can use and (2) using someone else's to build PETSc. to match the other package (say hypre already built)
> 
>    I don't see why (1) is a bad idea.
> 
> I think this is always a bad idea for the reasons I gave before, namely that due to the fragility it will
> break frequently, and we will get all the breakage on petsc-maint.
>  
>    Certainly we will ALL WAYS test any other package we use with PETSc but can we not use the information in that packages pkgconfig to tell us what compiler to use etc.?
> 
> I am not really against this. However, how would this work?

    We take their information and (try to) use it with a PETSc build, then we in our configure (as we do know) try to link in their library.

> It says one compiler in pkgconfig, but we have
> another from our config.

     There won't be another one in our config since we are building with their information!

> Are they the same? There is no simple way to tell. Are they compatible? Again, no
> simple test. Thus, it would always have to be what the user typed in already, so what are we saving?

   We are allowing people to (automatically when it works) build a version of PETSc that matches some package they already have installed. Yes this doesn't solve all the problems of the world but it is a nice feature.


   Barry

> 
>    Matt
>  
> 
>    Barry
> 
> On Nov 1, 2012, at 3:22 PM, Matthew Knepley <knepley at gmail.com> wrote:
> 
> > On Thu, Nov 1, 2012 at 3:56 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> > Bah, the problem with pkgconfig is that it doesn't handle different versions in different places well. We should use it in most cases, however.
> >
> > I disagree. There is only one way to be certain of a configure setting, and that is to test it. This will only
> > produce more mail from idiots who move their installation, or copy the config file, etc. There is no redeeming
> > value in this idea.
> >
> >    Matt
> >
> > On Nov 1, 2012 2:41 PM, "Matthew Knepley" <knepley at gmail.com> wrote:
> > On Thu, Nov 1, 2012 at 2:59 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> >
> >   Does, should, PETSc generate appropriate pkgconfig information for itself?  Does, can, it use that information from other packages?
> >
> > pkgconfig is too fragile to be of any use.
> >
> >    Matt
> >
> >
> >     Barry
> >
> >
> >
> >
> > --
> > What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> > -- Norbert Wiener
> >
> >
> >
> > --
> > What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> > -- Norbert Wiener
> 
> 
> 
> 
> -- 
> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> -- Norbert Wiener