Jörg Behrmann wrote:
How can I actually test whether Kwant uses mumps?
Try to “import kwant.solvers.mumps”. If this fails, the Kwant MUMPS solver does not work.
The only warning I get is about my scipy missing umfpack. Is that the appropriate runtime warning?
No, this is an independent thing.
If not a runtime warning about a missing mumps might be a good idea.
You might be right. MUMPS is not necessary for Kwant to work, and the performance of umfpack used to be quite OK for many applications. Now that umfpack is no longer included in SciPy, without MUMPS Kwant is indeed very slow.
Also, is mumps detected at build or runtime or has the build.conf be filled manually?
There is a very simple auto detection that works at least on Debian/Ubuntu [1]. In cases where this fails build.conf must be filled manually. If you can extend the auto detection to work on Arch as well, we will be more than happy to take this over.
Christoph
[1] http://git.kwant-project.org/kwant/tree/setup.py?h=stable&id=v1.0.4#n301