[Fedora-packaging] Ocaml sub-package issue

[Panu Matilainen]

On Thu, 1 Oct 2009, Richard W.M. Jones wrote:

> On Mon, Sep 28, 2009 at 04:33:24PM -0600, Orion Poplawski wrote:
>> I package plplot which ships bindings for oodles of languages, among
>> them perl and ocaml.  The ocaml packaging guidelines suggest:
>>
>> %global _use_internal_dependency_generator 0
>> %global __find_requires /usr/lib/rpm/ocaml-find-requires.sh
>> %global __find_provides /usr/lib/rpm/ocaml-find-provides.sh
>>
>> to add the required ocaml Requires/Provides.  However, this breaks the
>> automatic perl (and other?) generation for the perl sub-package.
>>
>> How should this be handled?  Is there a way to add the
>> ocaml-find-requires/provides to the normal list of providers?  Shouldn't
>> this be done automatically by the build system?
>
> Yes - really those should be pushed into upstream RPM.  However that
> isn't done at the moment.
>
> The reason for having the alternate dependency generator is to
> make dependencies of the form:
>
>  ocaml(Module) = MD5
>
> where MD5 is the md5sum of the dependent Module's interface (use
> 'ocamlobjinfo plplot.cma' to discover this).  This avoids the dreaded
> 'interface mismatch' error, and ensures that only a consistent set of
> packages can be installed together, which is good news if you are
> developing OCaml software that uses plplot.
>
> If you are willing to have the occasional inconsistent package set,
> you can just as easily forgo the above and simply add explicit
> dependencies on any packages you need, plus the ABI, eg:
>
>  Requires: ocaml-foo
>  Requires: ocaml(runtime) = 3.11.1
>
> This is still how Debian package things, although they are moving
> slowly to a system which is similar (but different in the details)
> from the one we use in Fedora.  In Debian you still get 'interface
> mismatch' errors.
>
> Really we need to get the OCaml dep generator into upstream RPM ...

I seem to recall commenting on this earlier (like at least a year ago :) 
but just as well I might've just intended to comment... anyway.
I would've pulled it to RPM upstream ages ago if it didn't have Fedora 
packaging specifics bolted in:

if [ -n "$emit_compiler_version" ]; then
     # Every OCaml program depends on the version of the
     # runtime which was used to compile it.
     echo "ocaml(runtime) = `cat /usr/lib*/ocaml/fedora-ocaml-release`"
fi

I suppose there's a reason why this is not generated with "ocaml -version" 
or "ocamlrun -version" as needed?

 	- Panu -