checkds test fails if Python < 3.7

Summary

If Python version is less than 3.7 and the dnspython module is installed, the checkds test fails with a Python error.

BIND version used

9.16.22

Steps to reproduce

Python version is 3.6 dnspython module is installed

./configure --prefix=/usr --sysconfdir=/etc --enable-static --localstatedir=/var --with-python=/usr/bin/python3.6
make -j $(nproc)
sudo bin/tests/system/ifconfig.sh up
make check

What is the current bug behavior?

The test fails with a Python error. See attached log.

What is the expected correct behavior?

The test succeeds, or at least doesn't have a Python error.

Relevant configuration files

Relevant logs and/or screenshots

See attached log of checkds test output. checkds.log

Possible fixes

The cause of the error is this line: bin/tests/system/checkds/tests-checkds.py#L78

The capture_output argument of the subprocess.run function was added in Python 3.7. Older versions of Python will fail with the error TypeError: __init__() got an unexpected keyword argument 'capture_output' as seen in the attached log.

A possible fix is to add an additional prerequisite check for the Python version being 3.7 or greater.