On Thu, Apr 11, 2013 at 9:17 AM, Satish Balay <[email protected]> wrote:

On Thu, 11 Apr 2013, Matthew Knepley wrote:

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On Wed, Apr 10, 2013 at 7:53 PM, Satish Balay <[email protected]> wrote:

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How do we handle these packages with complicated dependencies [they are complicated as petsc dependencies?]

In this report hdf5 was built with szip-2.1 and zlib-1.2.7. So how does petsc configure automatically detect this?

And I've recently used the following for hdf5/necddf5 on fusion [with the extra implicit depenceny of hdf5 on zlib, and netcdf5 on hdf5 from within configure]

'--with-hdf5-lib=-L/soft/hdf5/1.8.6-parallel/lib -lhdf5_hl -lhdf5 -lgpfs',

'--with-netcdf-lib=-L/soft/netcdf/4.1.1-parallel/lib -lnetcdff -lnetcdf -L/usr/kerberos/lib64 -lcurl -ldl -lgssapi_krb5 -lkrb5 -lk5crypto -lcom_err -lidn -lssl -lcrypto -lz',

Yeah - things work if the user knows the dependencies and the link command for those dependencies - and specify it to petsc configure as above. But I'm not sure how to autodetect this.

Also currently -lz is handled in package.py with 'self.needsCompression' similar to 'self.needsMath' with the detection of -lz in libraires.py:checkCompression() - but one can't specify a --with-zlib-lib option this way. I guess this part can be fixed by migrating it a standalone package z.py. [And somehow handle the optional part of this dependency for hdf5]

We already have a mechanism for this. Lots of packages depend on other packages. This is just screwed up in the case of libz because someone (maybe me) did not want to write an entire package file for it, and instead copped out with the needsCompression.

Currently we handle 'mandatory' dependencies properly - and optional

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depencencies for --download-pakcage somewhat - but not for --with-package-dir

For hdf5 - handling just zlib.py is not sufficient. Do we add szip.py, zlib.py, gpfs.py [and perhaps more] for hdf5? And somehow use these as optionaly when testing for user provided --with-hdf5? Which package currently implements this usage [to check for this optionaly dependency - and give the correct error]?

i.e In this case - when the user specified --with-hdf5-dir option. We had to print an error.: * please provide --with-zlib-dir and --with-szip-dir options. [For a different user - with the same usage - there would be no error]

For netcdf above one would have kerbros.py, curl.py and perhaps more?

We have had this same discussion a million times, and we always eventually get to the same answer and forget. Do we need our own error message for petsc-dev? We cannot possibly guess everything that can go wrong. What we need is a system where the user can specify what he actually wants and we check it. So, zlib and everything else are optional dependencies for hdf5. If something is not specified, it fails, and the user goes back and specifies the right thing. Matt

Satish

-- 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