start-compose.sh: No module named rpyc.core

[Zorilixer]

I cannot get Pupy to run with the provided start-compose.sh.
What am I doing wrong?

user@osboxes:~/pupy$ ./start-compose.sh
[+] Workdir: /home/user/pupy [UID=1001 GID=1001]
Starting pupy ... done
Attaching to pupy
pupy    | 2020-02-24 13:29:45,568| Datagram based stream is not available: KCP missing
pupy    | 2020-02-24 13:29:45,591| Datagram based stream is not available: KCP missing
pupy    | Traceback (most recent call last):
pupy    |   File "/opt/pupy/pupysh.py", line 83, in <module>
pupy    |     from pupylib import PupyServer
pupy    |   File "/opt/pupy/pupylib/__init__.py", line 21, in <module>
pupy    |     from PupyCmd import PupyCmdLoop
pupy    |   File "/opt/pupy/pupylib/PupyCmd.py", line 33, in <module>
pupy    |     from network.lib.base_launcher import LauncherError
pupy    |   File "/opt/pupy/network/lib/__init__.py", line 14, in <module>
pupy    |     from .streams.PupySocketStream import PupySocketStream
pupy    |   File "/opt/pupy/network/lib/streams/__init__.py", line 7, in <module>
pupy    |     from PupySocketStream import PupySocketStream
pupy    |   File "/opt/pupy/network/lib/streams/PupySocketStream.py", line 25, in <module>
pupy    |     from rpyc.core import SocketStream, Channel
pupy    | ImportError: No module named rpyc.core
pupy exited with code 1

Steps to reproduce:

1. Fresh/clean Debian 9.7 VirtualBox image from osboxes.org
2. ./install.sh - ok
3. ./start-compose.sh - failure
4. cd pupy/ && sudo -H pip install -r requirements.txt - ok
5. ./start-compose.sh - failure

(Side note: After pip install the native non-docker pupsh.sh works.)