in reply to Frontier::Client mystery result string hash

That doesn't look quite right. First off, are you doing:

print Dumper($result)
print Dumper([$result])
? If you're doing the former, that means $result is an array ref. The array so ref'd has one entry in it: a hash ref. That hash has a bunch of keys, including state, suffix, lat, and city. That is option #1. If you're doing the latter, then $result is a hash ref. This is option #2.

In option #1, you would find the city via: $result->[0]->{'city'} or, my preference, $result->[0]{'city'} (the quotes are optional in both cases).

In option #2, you would find the city as you attempted.

Either way, I'm not sure that your error is coming from the print statement. Can you come up with a minimal working script that shows your problem? You can skip Frontier::Client, if the problem isn't there, by setting up $result in your minimal script.