Supervisor Error: %(process_num) must be present within process_name when numprocs > 1

 Problem:

As the error description implies, this happens when you set the, numprocs to a value greater than 1.

e.g. numprocs=4



Solution:
Supervisor will start as many instances of this program as named by numprocs so you need to include %(process_num) in the value you for program_name so that process will have unique names.

e.g. process_name = %(program_name)s_%(process_num)02d


Now you can restart supervisor