Error: getaddrinfo: nodename nor servname provided

[jlconlin]

I installed this plugin using the ruby gem as instructed. I can't get it to work. Every time I've tried, I get the following message:

  Liquid Exception: Failed to open TCP connection to : (getaddrinfo: nodename nor servname provided, or not known) in //path/to/file/_posts/2022-04-26-April26.md

I thought I would try and run the tests as described. When I run the test I get the following output

$ ruby spec/integration_tests.rb                                                                                                                                                                                  [7:32:32]
<internal:/usr/local/Cellar/ruby/3.0.2_1/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require': cannot load such file -- byebug (LoadError)
        from <internal:/usr/local/Cellar/ruby/3.0.2_1/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
        from spec/integration_tests.rb:8:in `<main>'

I don't know ruby very well so I'm not sure what is happening here. Please advise