Issue with building parser - yacc error

[ag24in]

C:\Users\ACG9961.ATI\Downloads\smop-master\smop-master\smop>python main.py solver.m
ERROR: No token list is defined
Traceback (most recent call last):
File "main.py", line 16, in
import parse
File "C:\Users\ACG9961.ATI\Downloads\smop-master\smop-master\smop\parse.py", line 840, in
parser = yacc.yacc(start="top")
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python37_64\lib\site-packages\ply\yacc.py", line 3282, in yacc
raise YaccError('Unable to build parser')
ply.yacc.YaccError: Unable to build parser