I am experiencing hanging workflows on CentOS 7 and Ubuntu 18.04/20.04 [1-3].
I tried to debug them using a tmate session, but unfortunately, also tmate freezes.
The freeze happens in a python script (biodynamo run) which calls a cmake, make, run binary workflow.
Previously, I have also seen this behavior during valgrind tests, and during startup of an xvfb server.
Based on the latter one I found the following stackoverflow post which suggests to use tini as init process .
The workflow output shows defunct processes  (line 403), which atm I am unsure where they are coming from.
Do you think these defunct processes could cause these freezes?
Many thanks in advance for your help!
PS As a new user I am not allowed to include more than two links.
 github DOT com/BioDynaMo/biodynamo/pull/107/checks?check_run_id=927027188#step:5:2321
 github DOT com/BioDynaMo/biodynamo/pull/107/checks?check_run_id=927027213#step:5:2079