On Mon, Aug 17, 2015 at 4:20 AM, Ian Hinder ian.hinder@aei.mpg.de wrote:
On 17 Aug 2015, at 08:21, Roland Haas rhaas@aei.mpg.de wrote:
Hello all,
This happens a lot. It would be good to be able to put something into the optionlist which told the MPI thorn that it should use an auto-detected library, rather than building the library.
Most thorns support a XXX_DIR=NO_BUILD option which then (depends on the thorn) may require you to actually specify the location of the libraries or may still allow searching for it. Basically all auto-detection (with the exception of MPI which also seems to fail here) should fail on modern Debian/Ubuntu systems that support "multi-arch" installations since the libraries are no longer in /usr/lib but in /usr/lib/x86-amd64 or so. Bruno was working on fixing this before the last release but the results were too fragile to be included in the current release branch.
I know about the NO_BUILD option, but was under the impression that it doesn't do or mean what it appears to mean. I can't find any evidence of this at the moment, but I thought there were at least some thorns which would attempt to build anyway, even if you had set NO_BUILD. This would be the case if the thorn didn't know about the NO_BUILD option (external library handling is very nonuniform, with each library having to implement the same logic), but I thought it also happened for some thorns which did know about the option. I might be misremembering though.
As Roland says, setting MPI_DIR = NO_BUILD should do the trick.
Apart from this -- yes, some thorns don't support NO_BUILD, e.g. thorns F5 or LORENE which always build from source.
-erik