Re: Bug#657949: Cannot install libhdf5-mpi-dev and libnetcdf-dev
On 2012-02-02 01:43, Steve M. Robbins wrote:
> Hi,
>
> I'd like to contribute towards a solution for this. I'm forwarding to
> debian-devel to get some others' ideas.
> Naively, I don't understand why netcdf can't offer multiple variants,
> just as hdf5 does. Or, at least, one package libnetcdf-mpi-dev that
> links with the "default" MPI implementation.
>> I am not involved in the netcdf. You should report a bug on this
>> package.
> I'm prepared to do so, but I'd first like to get agreement that
> netcdf is where the problem lies. Netcdf maintainers, please
> chime in!
>
>
> I think we can no longer live in the status quo (see all the blockers
> of #631019), so something has to give. Even if it is painful, perhaps
> Debian could pioneer something and pass patches back to upstream?
>
> Thoughts?
>
> -Steve
>
As of now, I have several packages (eg ADIOS, CDO) that used to build
against netcdf and libhdf5-mpi-dev
that don't. Without fixes to netCDF (I appreciate what Francesco says
about netcdf upstream
not giving the libraries proper names), there needs to be a regression:
either the packages
build with netcdf but no MPI, or MPI but no netcdf.
I could split the package, and provide two versions, eg. adios-mpi and
adios-serial, but this to me is going backwards.
In an increasingly parallel world, we need binaries that will run in
parallel when its available. eg. detect
an MPI environmnent, and if so, use the parallel version of libraries.
Do others think this is the way to go, or that way lies madness?
That is, can we work out the details of what would be needed for
"automatic parallelism",
what we can do and what upstream changes might be needed?
e.g. we might add some shim code at the start of programs that do:
if (mpi_detected || ($ENV{NETCDF_SERIAL_WANTED})
dlopen(netcdf_mpi_version)
else
dlopen(netcdf_serial_version)
(Some netCDF programs, even running under MPI, might run in serial mode
in order to use
features such as compression that don't work in parallel netcdf).
We need to come up with:
(1) A bigger picture of where we want Debian to go (may involve upstream
changes)
(2) A plan for that we can do for the next release.
Regards
Alastair
--
Alastair McKinstry , <alastair@sceal.ie> , <mckinstry@debian.org> http://blog.sceal.ie
Anyone who believes exponential growth can go on forever in a finite world
is either a madman or an economist - Kenneth Boulter, Economist.
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