pgAdmin4 runtime error: linux

Built pgAdmin4 following the README runtime instructions and copied
pgAdmin4 and pgAdmin4.py to /usr/local/bin. When invoked the splash screen
displays and is immediately overlaid with an error message:

"An error occurred initializing the application server:
Failed to launch the application server, server thread exiting."

Clicking the "OK" button brings up a dialog box asking for the python and
application paths. I entered /usr/bin/python2 as the python path and left
the application path blank. Clicked the "OK" button.

The command line and results:

$ pgAdmin4
Python path: ""
Python Home: ""
Webapp path: "/usr/local/bin/pgAdmin4.py"
Traceback (most recent call last):
File "/usr/local/bin/pgAdmin4.py", line 23, in <module>
import config
ImportError: No module named config
"Failed to launch the application server, server thread exiting."

Please advise me how to fix this error. I've not installed all the brower
prerequisites with the understanding that the v.t. runtime did not require
flask, SQLAlchemy, and all the rest.

TIA,

Rich