This is purely for (manual) printf debugging. Hence, it is unused in the commited code.
The point is, to add printf statements to nmcli or libnm, like
if (getenv ("MY_HACK1")) { ...
and trigger it from test-client.py via
self.call_nmcli(..., extra_env = { 'MY_HACK1': '1' } )
Add a test which runs nmcli against our stub NetworkManager
service and compares the output.
The output formats of nmcli are complicated and not easily understood.
For example how --mode tabular|multiline interacts with selecting
output-fields (--fields) and output modes ([default]|--terse|--pretty).
Also, there are things like `nmcli connection show --order $FIELD_SPEC`.
We need unit tests to ensure that we don't change the output
accidentally.
