convert': undefined method convert_footnote'

[YenForYang]

I'm getting an error when trying to use kramdoc on this https://raw.githubusercontent.com/rust-lang/book/master/src/ch08-03-hash-maps.md:

C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:99:in `convert': undefined method `convert_footnote' for #<Kramdown::AsciiDoc::Converter:0x000000000588c200> (NoMethodError)
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:646:in `block in traverse'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:645:in `each'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:645:in `each_with_index'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:645:in `traverse'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:658:in `compose_text'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:193:in `convert_p'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:99:in `convert'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:646:in `block in traverse'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:645:in `each'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:645:in `each_with_index'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:645:in `traverse'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:105:in `convert_root'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/converter.rb:99:in `convert'
	from C:/ruby/gems/gems/kramdown-1.17.0/lib/kramdown/converter/base.rb:105:in `convert'
	from C:/ruby/gems/gems/kramdown-1.17.0/lib/kramdown/document.rb:117:in `method_missing'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/api.rb:52:in `convert'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/api.rb:104:in `convert_file'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/lib/kramdown-asciidoc/cli.rb:117:in `run'
	from C:/ruby/gems/gems/kramdown-asciidoc-1.0.1/bin/kramdoc:12:in `<top (required)>'
	from C:/apps/ruby/current/gems/bin/kramdoc:23:in `load'
	from C:/apps/ruby/current/gems/bin/kramdoc:23:in `<main>'

[YenForYang]

Seems like the issue only happens when using --format=GFM or --format=kramdown. --format=markdown doesn't produce the error.

However, using --format=markdown doesn't process the footnote properly on the page.

pandoc -s ch08-03-hash-maps.md -t asciidoctor actually seems to work correctly though here.

[mojavelinux]

Footnotes are not processed. In fact, I didn't even realize Markdown had footnotes.

[curiouslychase]

I also ran into this when converting some files (which is fine, I understand footnotes are not a part of any Markdown spec), but wanted to share that most people who use Footnotes are likely using markdown-it or remark with an extension such as markdown-it-footnote.