Re: purge_ld_conf.pl [Was: Re: the move to stublib]

[Sven LUTHER <luther@dpt-info.u-strasbg.fr>]

On Sun, Sep 08, 2002 at 03:45:59PM +0200, Denis Barbier wrote:
> On Sun, Sep 08, 2002 at 10:03:10AM +0200, Sven LUTHER wrote:
> [...]
> > Finally, the ocaml-base situation is solved by calling ocaml-ldconf by
> > hand in a postinst, as i do now.
> > 
> > What do you all think about it ?
> > 
> > Could someone knowledgeable in perl send me a modified dh_ocamlld that
> > does this ?
> 
> Sven, before jumping into details, we should:
>   a) define procedures to run on package install and upgrade
>   b) find how to implement these procedures without breaking
>      installed packages.

Huh ???

> I am at the moment confused by all the recent mails about this issue and
> unable to know what you have in mind.

Ok, let me recapitulate this :

  a) Old scheme libraries did add directories to /var/lib/ocaml/ld.conf
  during configure and remove them during remove. They failed to remove
  dirs during upgrade though.

  b) New scheme libraries put all stublibs in a common place, so no
  /var/lib/ocaml/ld.conf entry is needed.

  c) Saddly, due to the fact the old dh_ocamlld forgot to handle the
  removal of the directories of /var/lib/ocaml/ld.conf in an upgrade,
  the entries did not get removed when switching from a) libraries to b)
  libraries.

This last point is what we want to fix.

  o Stefano proposed to have a script scan all entries in
  /var/lib/ocaml/ld.conf and remove the ones corresponding to empty
  directories. This script would be centralized in a ocaml-base
  postinst, or whatever.

  o I feel it is better to handle this per package, so there is no need
  to scan the directories to see if they are empty or not, or whatever.
  I would have liked an option passing to dh_ocamlld so libraries can
  tell dh_ocamlld prior to which fixed version the removal script would
  need to be called. => I was told by you and Stefano that this was a
  too heavy thing to do.

So the idea is :

  o have dh_ocamlld check if the directory list passed to dh_ocamlld is
  empty or not:

    => it is not empty, do as usual (with the fixed script, which will
    handle upgrade also).

    => it is empty, then we use postinst-ocamlld-empty, which simply
    calls ocaml-ldconf -p<package_name> -R, and will remove all entries
    in /var/lib/ocaml/ld.conf corresponding to the package
    <package_name>.

I believe this to be quite easy to do (you would need a conditional
switch testing if @ARGV is empty or something) and a
postinst-ocamlld-empty script to be included in the empty case.

This will not break any installed package, will allow library packager
to fix the current problem by simply having a dh_ocamlld call with an
empty dirlist, and allow for a central place where the fix is found.

Friendly,

Sven Luther