> Do you have the new python3.7 installed from focal-proposed? > note, i was running everything from proposed. Since libffi6 & 7 might > be used by python3.7. Ah, no I didn't. However, doesn't seem like it makes much difference: ubuntu@ubuntu:~$ sudo apt install -t focal-proposed python3.7 Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: libpython3.7 libpython3.7-dbg libpython3.7-minimal libpython3.7-stdlib python3.7-dbg python3.7-minimal Suggested packages: python3.7-venv python3.7-doc python3-gdbm-dbg python3-tk-dbg binfmt-support The following packages will be upgraded: libpython3.7 libpython3.7-dbg libpython3.7-minimal libpython3.7-stdlib python3.7 python3.7-dbg python3.7-minimal 7 upgraded, 0 newly installed, 0 to remove and 72 not upgraded. Need to get 32.9 MB of archives. After this operation, 26.6 kB of additional disk space will be used. Do you want to continue? [Y/n] Get:1 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 python3.7-dbg arm64 3.7.6-1ubuntu2 [15.9 MB] Get:2 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 python3.7 arm64 3.7.6-1ubuntu2 [304 kB] Get:3 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libpython3.7 arm64 3.7.6-1ubuntu2 [1373 kB] Get:4 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libpython3.7-dbg arm64 3.7.6-1ubuntu2 [11.4 MB] Get:5 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libpython3.7-stdlib arm64 3.7.6-1ubuntu2 [1717 kB] Get:6 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 python3.7-minimal arm64 3.7.6-1ubuntu2 [1723 kB] Get:7 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libpython3.7-minimal arm64 3.7.6-1ubuntu2 [547 kB] Fetched 32.9 MB in 25s (1316 kB/s) (Reading database ... 80531 files and directories currently installed.) Preparing to unpack .../0-python3.7-dbg_3.7.6-1ubuntu2_arm64.deb ... Unpacking python3.7-dbg (3.7.6-1ubuntu2) over (3.7.6-1) ... Preparing to unpack .../1-python3.7_3.7.6-1ubuntu2_arm64.deb ... Unpacking python3.7 (3.7.6-1ubuntu2) over (3.7.6-1) ... Preparing to unpack .../2-libpython3.7_3.7.6-1ubuntu2_arm64.deb ... Unpacking libpython3.7:arm64 (3.7.6-1ubuntu2) over (3.7.6-1) ... Preparing to unpack .../3-libpython3.7-dbg_3.7.6-1ubuntu2_arm64.deb ... Unpacking libpython3.7-dbg:arm64 (3.7.6-1ubuntu2) over (3.7.6-1) ... Preparing to unpack .../4-libpython3.7-stdlib_3.7.6-1ubuntu2_arm64.deb ... Unpacking libpython3.7-stdlib:arm64 (3.7.6-1ubuntu2) over (3.7.6-1) ... Preparing to unpack .../5-python3.7-minimal_3.7.6-1ubuntu2_arm64.deb ... Unpacking python3.7-minimal (3.7.6-1ubuntu2) over (3.7.6-1) ... Preparing to unpack .../6-libpython3.7-minimal_3.7.6-1ubuntu2_arm64.deb ... Unpacking libpython3.7-minimal:arm64 (3.7.6-1ubuntu2) over (3.7.6-1) ... Setting up libpython3.7-minimal:arm64 (3.7.6-1ubuntu2) ... Setting up python3.7-minimal (3.7.6-1ubuntu2) ... Setting up libpython3.7-stdlib:arm64 (3.7.6-1ubuntu2) ... Setting up libpython3.7:arm64 (3.7.6-1ubuntu2) ... Setting up libpython3.7-dbg:arm64 (3.7.6-1ubuntu2) ... Setting up python3.7 (3.7.6-1ubuntu2) ... Setting up python3.7-dbg (3.7.6-1ubuntu2) ... Processing triggers for libc-bin (2.30-0ubuntu3) ... Processing triggers for man-db (2.9.0-2) ... Processing triggers for mime-support (3.64ubuntu1) ... ubuntu@ubuntu:~$ python3 -c "import goocalendar; print(goocalendar.__version__)" Segmentation fault (core dumped) I'll keep the SD card around for a few days if you want me to dig into this any further.