1 error in tests

[micwoj92]

Hello, I'm trying to run the test suite, but I run into 1 test error. ruby 3.0.6 nokogiri 1.13.9

Output when running rake:

Loaded suite /usr/lib/ruby/gems/3.0.0/gems/rake-13.0.6/lib/rake/rake_test_loader
Started
Coverage report generated for Unit Tests to /home/micwoj92/Documents/pkg/fog/simplecov-cobertura/tmp/coverage.xml. 6 / 7 LOC (85.71%) covered; 3 / 6 BC (50.00%) covered
E
==============================================================================================================================================================================================================================================
Error: test_format_dtd_validates(CoberturaFormatterTest): NoMethodError: undefined method `validate' for nil:NilClass
/home/micwoj92/Documents/pkg/fog/simplecov-cobertura/test/simplecov-cobertura_test.rb:56:in `test_format_dtd_validates'
     53:     xml = @formatter.format(@result)
     54:     options = Nokogiri::XML::ParseOptions::DTDLOAD
     55:     doc = Nokogiri::XML::Document.parse(xml, nil, nil, options)
  => 56:     assert_empty doc.external_subset.validate(doc)
     57:   end
     58: 
     59:   def test_no_groups
==============================================================================================================================================================================================================================================
Coverage report generated for Unit Tests to /home/micwoj92/Documents/pkg/fog/simplecov-cobertura/tmp/cobertura.xml. 6 / 7 LOC (85.71%) covered; 3 / 6 BC (50.00%) covered
|Coverage report generated for Unit Tests to /home/micwoj92/Documents/pkg/fog/simplecov-cobertura/tmp/coverage.xml. 6 / 7 LOC (85.71%) covered; 3 / 6 BC (50.00%) covered
/Coverage report generated for Unit Tests to /home/micwoj92/Documents/pkg/fog/simplecov-cobertura/tmp/coverage.xml. 6 / 7 LOC (85.71%) covered; 3 / 6 BC (50.00%) covered
-Coverage report generated for Unit Tests to /home/micwoj92/Documents/pkg/fog/simplecov-cobertura/tmp/coverage.xml. 6 / 7 LOC (85.71%) covered; 3 / 6 BC (50.00%) covered
\Coverage report generated for Unit Tests to /tmp/tmp/coverage.xml. 6 / 7 LOC (85.71%) covered; 3 / 6 BC (50.00%) covered
Finished in 0.137903972 seconds.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
7 tests, 66 assertions, 0 failures, 1 errors, 0 pendings, 0 omissions, 0 notifications
85.7143% passed
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
50.76 tests/s, 478.59 assertions/s
rake aborted!
Command failed with status (1)

Tasks: TOP => default => test
(See full trace by running task with --trace)