Hi Ludo and Eric,
I think it is helpful to consider this question in two ways; thinking
about the short term and the longer term.  I think in the short term it
is best to stick with the OpenFOAM-standard layout, modified in the
'middle-road' way suggested earlier.  On top of the previous points
made, there is an additional advantage to this approach in that the
OpenFOAM-standard layout has been thoroughly tested in production use
over many years.
In the longer term I think it would be possible to develop a Guix-
standard layout.  I cannot see any reason why this would not work.
 However, with a large system such as OpenFOAM, this may not
necessarily be an easy task.  I see this as principally an upstream
job, since they are the most knowledgeable people on the current layout
and are best placed to deal with any subleties involved.  With a
working Guix package in place it will be a good time to contact
upstream and discuss the merits of a new layout.
Today I hope to finish the package definition.  I have placed the tree
under the 'lib' directory and this allows the 'validate-runpath' phase
to run.  The phase currently fails as ld-wrapper does not add the
runpaths of the shared objects in the build tree.  I plan to use
patchelf to fix this.
Paul.
On Fri, 2017-09-08 at 22:30 +0200, Ludovic Courtès wrote:
> Hi Eric,
> 
> Eric Bavier <ericbavier@centurylink.net> skribis:
> 
> > 
> > It seems to me that if using Guix's profiles and environments, we
> > could entirely do without OpenFOAM's installation directories and
> > simply install into a standard bin/lib structure.  Just install
> > libraries into (string-append %output "/lib") and the binaries into
> > (string-append %output "/bin").
> Fair enough.  I guess the question is more whether (1) this would
> work
> :-), and (2) whether seasoned OpenFOAM users would be happy with
> this.
> 
> WDYT, Paul?
> 
> Ludo’.