cannot import name 'BisonParser' from 'bison'

[yh0508619]

When trying to run the javaparser.py with python3.9
the following error message pops up:
cannot import name 'BisonParser' from 'bison'

Does anyone encounter the same problem?

Run in Ubuntu 18.04
Bison, Flex, and Pybison have been installed using pip3

[sbrodehl]

Hey @yh0508619,

which pybison version do you use and what is the exact command you execute, which produces the error above?