As I cannot reproduce the error on my Jupyter notebook, I can only guess why the message from subprocess is not shown. Given that the main process prints “done”, I would assume the sub-processes are launched correctly. But since the subprocess didn’t print the message, it could be either 1) sub-process crashed 2) sub-process is not printing to stdout. For 1), you can check the exitcode of the subprocess, adding more logs will also help. For 2) you will need check local configures to see if it is redirected, or you explicitly redirect that print to file.