Re: gfortran transition: new lapack and blas questions

["Kevin B. McCarty" <kmccarty@Princeton.EDU>]

Hi Matthias and Camm,

Matthias Klose wrote:
> Kevin B. McCarty writes:

>> 1) Build-dependencies, and dependencies of Cernlib -dev packages, should
>> look like this:
>>
>> Depends: refblas3-dev (>= 1.2-9) | libblasgf-3.so
>> Depends: lapack3-dev (>= 3.1.1-0.1) | liblapackgf-3.so
> 
> why the '| libblasgf-3.so'? This alternative doesn't provide any -dev
> files.

I thought it was precisely the point of the BLAS/LAPACK/ATLAS virtual
packages named like "*.so" to be supplied by the -dev packages??


>> 2 Packages that want to manually depend upon BLAS or LAPACK runtime
>> libraries (not devel files) without using shlibs should have deps like this:
>>
>> Depends: refblas3gf | libblasgf.so.3
>> Depends: lapack3gf | liblapackgf.so.3
> 
> is there a reason not to use dpkg-shlibdeps?

Since you and Camm both asked this, I should probably answer it.

Basically I'm trying to get people who install Cernlib meta-packages to
end up with the refblas3 and lapack3 runtime library packages, rather
than the ATLAS runtime libraries that take up significantly more disk space:

refblas3 = 225 kB
lapack3  = 2.6 MB
atlas3-base = 6.4 MB

I can't control what's in these packages' shlibs, but I can put refblas3
and lapack3 as the first alternative in the meta-package dependency
line, so that the dependency is already fulfilled by the time APT
reaches the dependency that has the shlibs.

For example:

* the cernlib-core meta-package depends on:

... refblas3 | libblas.so.3, lapack3 | liblapack.so.3, paw++, ...

* paw++ depends on (pulled in by ${shlibs:Depends}):

atlas3-base | lapack3 | liblapack.so.3, ...

The end result is that users who install Cernlib via the meta-packages
end up with only the BLAS/LAPACK runtime libs if they do not already
have anything satisfying this dependency installed, but nevertheless
ATLAS will satisfy the dependency if they've already installed it for
other reasons.

Do you consider this to be a bad idea?  Should I not mess with things
this way (so that users will end up with ATLAS by default)?

best regards,

-- 
Kevin B. McCarty <kmccarty@princeton.edu>   Physics Department
WWW: http://www.princeton.edu/~kmccarty/    Princeton University
GPG: public key ID 4F83C751                 Princeton, NJ 08544