JUnit Parses generating empty file [CirlceCI]

[coding-bunny]

RuboCop 0.80.0 is not generating the correct file output with the new JUnit formatter.

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Expected behavior

I expected the generated files for RuboCop JUnit to contain at least an entry to allows me to report back to CircleCI the amount of files inspected and no offenses found

Actual behavior

Right now the JUnit report is empty, and CircleCI doesn't accept it as a valid test-result report.

Steps to reproduce the problem

Run RuboCop with the following configuration:

bundle exec rubocop --format junit --out tmp/test-results/rubocop/results.xml

This products an empty XML file:

<?xml version='1.0'?>
<testsuites>
  <testsuite name='rubocop'/>
</testsuites>

RuboCop version

0.80.0

$ [bundle exec] rubocop -V
0.80.0 (using Parser 2.7.0.2, running on ruby 2.6.5 x86_64-darwin19)

[coding-bunny]

As example