packaging mpich2 -- conflicts with lam and file layoutb

[Ralf Corsepius]

On Tue, 2005-11-08 at 13:14 -0500, Ed Hill wrote:
> On Tue, 2005-11-08 at 18:37 +0100, Enrico Scholz wrote: 
> > ed at eh3.com (Ed Hill) writes:
> > 
> > > I want multiple MPI implementations installed side-by-side and I
> > > want to select, for instance, which "mpirun" is called on a ***
> > > per-session basis *** by either specifying its full path or by using
> > > some semi-automated ${PATH} manipulation magic such as:
> > > ...
> > > So, my question for the packaging-gurus becomes:  Is there some way that
> > > we can accomplish that using something like (that is, similar but
> > > perhaps not exactly the same as):
> > >
> > >   /usr/lib/${MPI_IMPL_NAME}/{bin,man,lib,include}
> > 
> > You could create binaries like
> > 
> > | /usr/bin/lam-mpiCC
> > | /usr/bin/mpich2-mpiCC
> > 
> > These binaries are settings correct $PATHs (resp. this should not be
> > needed when the packages are configured with correct paths).
> > 
> > In simplest case, the binaries are sym- or hardlinks like
> > 
> > /usr/bin/mpich2-mpiCC -> ../lib/mpich2/bin/mpiCC
> 
> 
> Hi Enrico & Jeff,
> 
> Thanks for the comments!  I suppose the above linking scheme is the best
> that can be done for binaries.  While it is somewhat annoying, it does
> allow the binaries for multiple MPI implementations to co-exist which is
> sufficient for side-by-side installs.

Reasonably packaged packages support --program-prefix=<whatever>,
exactly for this purpose. I don't know if mpich2 or one of its
competitors supports it.

> So, that leaves one issue -- what should be done about the man pages?
> The different MPI implementations have different man pages not only for
> the binaries but also for much of the MPI API (all the functions which
> obviously have the same names across implementations).  Can the man
> pages be somehow renamed and/or relocated?

Firstly, all application man pages should correspond to the actual
binaries. So, if you should rename the applications, you probably also
should consider to rename the man-pages.

Secondly, you could rename the man-pages to using a different man suffix
suffix, eg. .3mpich instead of .3.

If these packages' developers have designed their package for parallel
installation to their competitors, they already should have done this.
If not, this is a strong indication for this package not being prepared
for parallel installation.

>   Or should they be converted
> to html pages or totally ignored or ...?
;)

Well, all in all it's quite simple: You have 2 choices:
1. Tweak the package for parallel installation
2. Package it as alternative to its competitors

Ralf