kerberos.so is not generated by setup.py

When installing from source, kerberos.so is not generated by `python setup.py install` is ran. This was replicated with 0.3.18, .17, .11 and .0 zip files also latest on master branch.

Dockerfile of Ubuntu18 container I attempted this in:

FROM ubuntu:18.04
RUN apt-get -y update && apt-get -y install sudo net-tools curl unzip
RUN apt-get install -y --no-install-recommends python-dev build-essential python2.7 python3 python-pip py3c-dev python3-pip
RUN apt-get install -y python3-dev
RUN apt-get install -y --no-install-recommends libkrb5-dev
RUN pip3 install setuptools
RUN pip3 install pycryptodomex
RUN apt-get -y install silversearcher-ag git
RUN git clone https://github.com/emc-isilon/pike.git
WORKDIR pike
RUN python3 setup.py install
RUN ls; sleep 10
WORKDIR /pike/build/temp.linux-aarch64-3.6/pykerb
RUN ag -g kerberos.so; sleep 10
RUN ls; ls -l; sleep 10
WORKDIR /pike
RUN ag -g kerberos.so; sleep 10