Running fedpkg lint in version 0.5.2.0:

{{{
$ /usr/bin/fedpkg lint
Traceback (most recent call last):
File "/usr/bin/fedpkg", line 1250, in <module>
args.command(args)
File "/usr/bin/fedpkg", line 559, in lint
return mymodule.lint(info)
NameError: global name 'info' is not defined
$
}}}

Looking at the source, it turns out the info variable is indeed not defined anywhere.