On Thu, 11 Apr 2013, Matthew Knepley wrote:

> On Thu, Apr 11, 2013 at 9:17 AM, Satish Balay <balay@mcs.anl.gov> wrote:
>
> > On Thu, 11 Apr 2013, Matthew Knepley wrote:
> >
> > > On Wed, Apr 10, 2013 at 7:53 PM, Satish Balay <balay@mcs.anl.gov> wrote:
> > >
> > > > 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
> > >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.

Sure - but specify how? specify everything with --with-hdf5-lib,--with-hdf5-include options?

Or somehow he knows that he has to specify --with-zlib-include/-with-zlib-lib options?

This thread started becasue one expected --with-hdf5-dir to be
sufficient - and its not.  current workarround [becuase of
self.needsCompression] is to specify zlib with LIBS otpions - and all
other dependencies with --with-hdf5-lib. It works - but if were were
satisfactory - this whole thread on petsc-dev wouldn't arise.

Satish