undefined local variable crashes when fetch_img_data fails

I'm seeing some bugs in error handling when we have failures fetch_img_data in the MermaidProcessor.

Reproduction case

misconfigure the mermaid-process to trigger http errors. In _config.yaml:
```
plugins:
- jekyll-spaceship
```

jekyll-spaceship: mermaid-processor: mode: "pre-fetch" src: "http://does-not-exist/svg/"

* add two pages, one with a mermaid diagram
* run `jekyll build`

Expected behavior: we log a "Failed to open TCP connection to does-not-exist" error and continue processing the other file

Actual behavior: we catch the "Failed to open..." error and then throw an unhandled error trying to log, which crashes `jekyll`:

/usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/processor.rb:215:in rescue in fetch_img_data': undefined local variable or methodlogger' for Jekyll::Spaceship::MermaidProcessor:Class (NameError) from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/processor.rb:203:in fetch_img_data' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:70:inhandle_mermaid' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:56:in block in handle_mermaid_block' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:47:inscan' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:47:in handle_mermaid_block' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:39:inblock in on_handle_markdown' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:38:in each' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:38:inon_handle_markdown' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/processor.rb:118:in dispatch' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:61:inblock in dispatch' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:60:in each' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:60:indispatch' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:32:in block in hook' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:48:inblock in hook' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/hooks.rb:99:in block in trigger' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/hooks.rb:98:ineach' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/hooks.rb:98:in trigger' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/page.rb:181:intrigger_hooks' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/renderer.rb:61:in run' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:532:inrender_regenerated' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:524:in block in render_pages' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:523:ineach' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:523:in render_pages' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:208:inrender' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:80:in process' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:28:inprocess_site' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/commands/build.rb:65:in build' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/commands/build.rb:36:inprocess' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:91:in block in process_with_graceful_fail' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:91:ineach' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:91:in process_with_graceful_fail' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/commands/serve.rb:86:inblock (2 levels) in init_with_program' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:in block in execute' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:ineach' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:in execute' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/program.rb:44:ingo' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary.rb:21:in program' from /usr/gem/gems/jekyll-4.1.1/exe/jekyll:15:in<top (required)>' from /usr/local/bundle/bin/jekyll:29:in load' from /usr/local/bundle/bin/jekyll:29:in

' /usr/local/lib/ruby/2.7.0/net/http.rb:960:in

initialize': Failed to open TCP connection to does-not-exist:80 (getaddrinfo: Name does not resolve) (SocketError) from /usr/local/lib/ruby/2.7.0/net/http.rb:960:in

open' from /usr/local/lib/ruby/2.7.0/net/http.rb:960:in block in connect' from /usr/local/lib/ruby/2.7.0/timeout.rb:95:inblock in timeout' from /usr/local/lib/ruby/2.7.0/timeout.rb:105:in timeout' from /usr/local/lib/ruby/2.7.0/net/http.rb:958:inconnect' from /usr/local/lib/ruby/2.7.0/net/http.rb:943:in do_start' from /usr/local/lib/ruby/2.7.0/net/http.rb:932:instart' from /usr/local/lib/ruby/2.7.0/net/http.rb:606:in start' from /usr/local/lib/ruby/2.7.0/net/http.rb:481:inget_response' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/processor.rb:205:in fetch_img_data' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:70:inhandle_mermaid' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:56:in

block in handle_mermaid_block' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:47:in

scan' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:47:in

handle_mermaid_block' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:39:in

block in on_handle_markdown' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:38:in each' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:38:inon_handle_markdown' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/processor.rb:118:in dispatch' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:61:inblock in dispatch' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:60:in each' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:60:indispatch' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:32:in block in hook' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/manager.rb:48:inblock in hook' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/hooks.rb:99:in block in trigger' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/hooks.rb:98:ineach' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/hooks.rb:98:in trigger' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/page.rb:181:intrigger_hooks' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/renderer.rb:61:in run' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:532:inrender_regenerated' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:524:in block in render_pages' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:523:ineach' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:523:in render_pages' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:208:inrender' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/site.rb:80:in process' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:28:inprocess_site' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/commands/build.rb:65:in build' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/commands/build.rb:36:inprocess' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:91:in block in process_with_graceful_fail' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:91:ineach' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/command.rb:91:in process_with_graceful_fail' from /usr/gem/gems/jekyll-4.1.1/lib/jekyll/commands/serve.rb:86:inblock (2 levels) in init_with_program' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:in block in execute' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:ineach' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:in execute' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary/program.rb:44:ingo' from /usr/gem/gems/mercenary-0.4.0/lib/mercenary.rb:21:in program' from /usr/gem/gems/jekyll-4.1.1/exe/jekyll:15:in<top (required)>' from /usr/local/bundle/bin/jekyll:29:in load' from /usr/local/bundle/bin/jekyll:29:in

' /usr/local/lib/ruby/2.7.0/net/http.rb:960:in initialize': getaddrinfo: Name does not resolve (SocketError) from /usr/local/lib/ruby/2.7.0/net/http.rb:960:inopen' from /usr/local/lib/ruby/2.7.0/net/http.rb:960:in block in connect' from /usr/local/lib/ruby/2.7.0/timeout.rb:95:inblock in timeout' from /usr/local/lib/ruby/2.7.0/timeout.rb:105:in timeout' from /usr/local/lib/ruby/2.7.0/net/http.rb:958:inconnect' from /usr/local/lib/ruby/2.7.0/net/http.rb:943:in do_start' from /usr/local/lib/ruby/2.7.0/net/http.rb:932:instart' from /usr/local/lib/ruby/2.7.0/net/http.rb:606:in start' from /usr/local/lib/ruby/2.7.0/net/http.rb:481:inget_response' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/cores/processor.rb:205:in fetch_img_data' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:70:inhandle_mermaid' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:56:in

block in handle_mermaid_block' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:47:in

scan' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:47:in

handle_mermaid_block' from /usr/gem/gems/jekyll-spaceship-0.9.5/lib/jekyll-spaceship/processors/mermaid-processor.rb:39:in



## Analysis

The error is thrown from https://github.com/jeffreytse/jekyll-spaceship/blob/e1a5bf7356b0292022a430dd6cea9daab625bc35/lib/jekyll-spaceship/cores/processor.rb#L208

I'm not very familiar with ruby OO, but it seems like the base class's `initialize` to set the logger https://github.com/jeffreytse/jekyll-spaceship/blob/f9a9a658e8f0f2d5cba84d36ac43b720b16cc4bc/lib/jekyll-spaceship/cores/processor.rb#L43 is somehow not taking effect in sub-classes like `MermaidProcessor`?

Or maybe the way we call `fetch_img_data` inside `MermaidProcessor` is somehow changing the context and losing a reference to the logger? https://github.com/jeffreytse/jekyll-spaceship/blob/f9a9a658e8f0f2d5cba84d36ac43b720b16cc4bc/lib/jekyll-spaceship/processors/mermaid-processor.rb#L70

jeffreytse / jekyll-spaceship

undefined local variable crashes when fetch_img_data fails #35

Reproduction case