[petsc-dev] PETSC_DIR and PETSC_ARCH: used to distinguish between multiple applications ?

[Kevin Buckley]

On 24 April 2017 at 15:21, Jed Brown <jed at jedbrown.org> wrote:

> There is no harm in including all external packages that you might need.
>
>> In terms of laying out PETSc, can (should ?) one use PETSC_DIR
>> and PETSC_ARCH: to combine everything PETSc-related under one,
>> top-level, say
>>
>> /path/to/PETSC/3.7.5
>
> No, you can only install one configuration to a given prefix.  Note that
> when you do a "prefix install" (./configure
> --prefix=/path/to/PETSc/3.7.5), there is no PETSC_ARCH once you have
> installed.  And you can't have two conflicting configurations in the
> same prefix, so you probably need a schema something like below (if you
> really need multiple configurations, which you may not).
>

Cheers for that.

What muddied the waters slightly, as regards the "external PETSc packages"
for different PETSc-using packages was that I had seen a version difference
between the latest PETSc and the latest version of the package in question,
BISICLES.

It wasn't clear to me whether a package that relies on PETSc should try
and match the PETSc dependencies if it has any in common.

The authors of BISICLES suggest that there shouldn't be any interaction
between their package's use of, in this case NetCDF, and PETSc's use
of it, so the question is probably moot, however, when one is installing
a software stack, things like that do get you (wel, me anyway) thinking.

Thanks to all for the feeback on this thread: it has been informative
Kevin