[Users] hwloc: necessary?; explicit dependencies

[Bernard Kelly]

Hi all.

Trying to compile the current ETK release on the NASA Ames machine
Pleiades, I ran into issues with hwloc. This isn't present on the
cluster, so I was using the standard "BUILD" option in my config file.
The result was a lot of missing symbol messages at link time.

I found that I could get past this by just not compiling hwloc at all,
which prompts two new questions for me:

(1) When do I *need* hwloc? Is it only relevant to systems using
OpenMPI? The machine Pleiades uses SGI mpi.

(2) More generally, I try to assess module dependencies from what
appears in the auto-generated Thornlist. But you can't tell from this
that *any* other thorn depends on hwloc. In particular, SystemTopology
shows no dependencies at all:

CactusUtils/SystemTopology         # SystemTopology ( ) [ ] { }

...  but compilation without hwloc fails immediately unless I comment
out SystemTopology as well.

Can hidden dependencies like this be improved?

Thanks, Bernard

--
------------------------------------------------------------------
Bernard Kelly -- CRESST Assistant Research Scientist, NASA/GSFC
Gravitational Astrophysics Laboratory --- Code 663

Phone: +1 (301) 286-7243 *** Fax: +1 (301) 286-2226
Web: http://science.gsfc.nasa.gov/sed/bio/bernard.j.kelly
ORCID: orcid.org/0000-0002-3326-4454
------------------------------------------------------------------