Dear Kwant developers I am having problems with the installation of kwant in linux mint 19.1 I tried to installed the pre-build package of kwant on my computer but I faced problems with the dependencies. This is what I did: 1. Inserted the lines below in the sources.list file located in /etc/apt/ deb [trusted=yes] http://ftp.debian.org/debian stretch-backports main deb [trusted=yes] http://downloads.kwant-project.org/debian/ stretch-backports main deb-src [trusted=yes] http://downloads.kwant-project.org/debian/ stretch-backports main 2. Executed the commands below as superuser apt-get update apt-get -t stretch-backports install python3-kwant python-kwant-doc and this was the output The following packages have unmet dependencies: python3-kwant : Depends: python3 (< 3.6) but 3.6.7-1~18.04 is to be installed Depends: libmumps-4.10.0 but it is not installable Depends: libmumps-scotch-4.10.0 but it is not installable E: Unable to correct problems, you have held broken packages. Since the pre-build package option did not work, I decided to try to build the package from source. This is what I did: 1. Move to the /tmp folder 2. Executed successfully the command, apt-get build-dep tinyarray kwant 3. Executed successfully the command, apt-get source --compile tinyarray 3. Had a problem with the command apt-get source --compile kwant, that showed me the following error There is a programable error in your configuration file: Traceback (most recent call last): File "/tmp/kwant-1.4.0/debian/python3-kwant/usr/lib/python3.6/dist-packages/kwant/qsymm.py", line 21, in <module> import qsymm ModuleNotFoundError: No module named 'qsymm' The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/usr/lib/python3/dist-packages/sphinx/config.py", line 157, in __init__ execfile_(filename, config) File "/usr/lib/python3/dist-packages/sphinx/util/pycompat.py", line 150, in execfile_ exec_(code, _globals) File "conf.py", line 22, in <module> import kwant.qsymm File "/tmp/kwant-1.4.0/debian/python3-kwant/usr/lib/python3.6/dist-packages/kwant/qsymm.py", line 30, in <module> raise ImportError(msg) from error ImportError: 'kwant.qsymm' is not available because one or more of its dependencies is not installed. Makefile:72: recipe for target 'html' failed make[2]: *** [html] Error 1 make[2]: Leaving directory '/tmp/kwant-1.4.0/doc' debian/rules:25: recipe for target 'override_dh_installdocs' failed make[1]: *** [override_dh_installdocs] Error 2 make[1]: Leaving directory '/tmp/kwant-1.4.0' debian/rules:7: recipe for target 'binary' failed make: *** [binary] Error 2 dpkg-buildpackage: error: fakeroot debian/rules binary subprocess returned exit status 2 E: Build command 'cd kwant-1.4.0 && dpkg-buildpackage -b -uc' failed. I tried to install separately the module qsymm but I couldn't. The instruction pip install qsymm did not work. Kind regards, Leo