<html>#2969: ExternalLibraries-PETSc: Link hwloc into the configure-time MPI check for from-source MPI
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<tr><td style='text-align:right'> Reporter:</td><td>Max Morris</td></tr>
<tr><td style='text-align:right'> Status:</td><td>open</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td></td></tr>
<tr><td style='text-align:right'> Type:</td><td>bug</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>major</td></tr>
<tr><td style='text-align:right'>Component:</td><td></td></tr>
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<p>Comment (by Max Morris):</p>
<p>When building HDF5 via the ExternalThorn, only serial HDF5 is built, so the issue is sidestepped. See src/build.sh:77 in ExternalThorn-MPI, there is no --enable-parallel flag when calling <code>./configure</code> and I don't see any way for that flag to arrive there. The only instance where parallel HDF5 is linked against MPI is during the final Cactus linkage (ExternalThorn-MPI's src/detect.sh:269 checks for parallel HDF5 and adds MPI libdirs to its own), by which point hwloc is present on the link line anyway as I mentioned previously. If ExternalThorn-HDF5 were to build with --enable-parallel then I suspect it would suffer from the same issue as PETSc.</p>
<p>I still think you are right that the fix ought to live in the MPI thorn. I am currently building Cactus with such a fix to make sure it works before submitting a new PR.</p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2969/externallibraries-petsc-link-hwloc-into'>https://bitbucket.org/einsteintoolkit/tickets/issues/2969/externallibraries-petsc-link-hwloc-into</a></p>
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