Hi all, what follows is a short story about installing kwant 1.2.2 on Fedora 24. So, I installed kwant 1.2.2. and all necessary dependencies with pip. In particular, I also installed MUMPS-devel – not with pip, obviously, but with the Fedora package manager dnf, which automatically also installs the packages MUMPS and MUMPS-common. However, after finishing the installation and trying to import kwant, the following warning appeared: /home/nefta/.virtualenvs/testKwant/lib/python3.5/site-packages/kwant/solvers/default.py:18: RuntimeWarning: MUMPS is not available, SciPy built-in solver will be used as a fallback. Performance can be very poor in this case. "Performance can be very poor in this case.", RuntimeWarning) Seems like kwant could not link against the already installed MUMPS-devel libraries. To solve that, Joe and I removed kwant and installed it again but this time from source and created a build.conf file that contains the following lines: [mumps] libraries = zmumps mumps_common include_dirs = /usr/include/MUMPS This seemed to fix it. So, if you are using Fedora 24 and want to use kwant with MUMPS and do not want to install conda for reasons, that is a possible workaround. Cheers, Nefta