Re: How is mpi-default-dev supposed to work?
On 24/03/10 at 10:04 +0100, Thibaut Paumard wrote:
> Le 23 mars 10 à 19:40, Lucas Nussbaum a écrit :
> >I think that the best way to solve this problem is to explicitely
> >conflict with the other implementations in mpi-defaults. I don't
> >see any
> >other solution that really fixes the problem we are having and doesn't
> >require an upload of all packages using mpi-defaults.
> I thought about that a little bit more carefully and I think it is a
> dangerous solution that may lead to many FTBFSes. At least it needs
> to be tested.
> The problem is that is that the way dpkg chooses between two
> conflicting packages may not be what we expect. What we want is that
> dpkg always installs the last package selected for installation,
> uninstalling the one installed:
> - if mpich2 is installed and installation of mpi-default-dev is
> requested, uninstall mpich2;
> - if mpi-default-dev is installed and installation of mpich2 is
> requested, uninstall mpi-default-dev.
> Is it what will happen in practice? I'm afraid that the opposite
> will happen: dpkg may well refuse to install the new package because
> a conflicting package is already installed. I believe what we want
> to do requires a combination of Conflicts, Provides and Replaces
> that will be hard if not impossible to put in place.
dpkg might refuse to do that, but it's apt-get which matters here.
| Lucas Nussbaum
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