Re: [Cpanplus-devel] Advice requested; Automatic building of debian packages from CPAN modules

[Michael G Schwern <schwern@pobox.com>]

On Tue, Dec 07, 2004 at 01:27:02PM +0000, Stephen Quinney wrote:
> > I believe simply setting "Replaces: perl-modules, perl-base, perl" in any
> > CPAN module which has a default INSTALLDIRS of "perl" should do the trick.
> 
> My understanding of it is that you can only use 'Replaces' if you are
> replacing the _whole_ of that package. perl-modules is a set of
> packages and as such 'Replaces' various packages. However, one of
> those packages on their own would not replace the whole of
> perl-modules though.

If I'm reading the packaging manual correctly you can use Replaces to
replace individual files as well as whole packages.
http://www.debian.org/doc/debian-policy/ch-relationships.html#s7.5.1

I believe the difference lies in whether or not the two packages also
Conflict.

"If one package is to be installed, the other must be removed first - if the 
package being installed is marked as replacing the one on the system... then 
dpkg will automatically remove the package which is causing the conflict"

http://www.debian.org/doc/debian-policy/ch-relationships.html#s-conflicts

But I'm just reading the manual, I could be wrong.


"update-alternatives" seems the wrong way to handle this.  These are not
really two alternative implementations (as, for example, nvi and vim) they
are two packages shipping possibly different versions of the same program.


-- 
Michael G Schwern        schwern@pobox.com  http://www.pobox.com/~schwern/
You're more radiant than a memory of breathtaking ecstasy.