After following the instructions pretty successfully up to this point I find I can’t do a mix docs with the configuration given. I’m not sure what to do to get Earmark to work in this case.

When I ran mix docs as shown on page 167 I got the following:

Generating docs...
** (FunctionClauseError) no function clause matching in EarmarkParser.Helpers.LookaheadHelpers.has_still_opening_backtix/2

    The following arguments were given to EarmarkParser.Helpers.LookaheadHelpers.has_still_opening_backtix/2:

        # 1
        [verbatim: "Handle the command line parsing and the dispatch to"]

        # 2
        nil

    Attempted function clauses (showing 8 out of 8):

        defp has_still_opening_backtix(-[]-, -:force_outside-)
        defp has_still_opening_backtix(-[]-, +open+)
        defp has_still_opening_backtix(-[{:other, _} | rest]-, +nil+)
        defp has_still_opening_backtix(-[{:backtix, btx} | rest]-, +nil+)
        defp has_still_opening_backtix(-[{:escape, _} | rest]-, +nil+)
        defp has_still_opening_backtix(+[_ | rest]+, -:force_outside-)
        defp has_still_opening_backtix(-[{:backtix, btx} | rest]-, -open = {_, openedbtx}-)
        defp has_still_opening_backtix(+[_ | rest]+, -open = {_, _}-)

    (earmark_parser 1.4.12) lib/earmark_parser/helpers/lookahead_helpers.ex:45: EarmarkParser.Helpers.LookaheadHelpers.has_still_opening_backtix/2
    (earmark_parser 1.4.12) lib/earmark_parser/helpers/lookahead_helpers.ex:17: EarmarkParser.Helpers.LookaheadHelpers.opens_inline_code/1
    (earmark_parser 1.4.12) lib/earmark_parser/parser.ex:531: EarmarkParser.Parser._inline_or_text?/2
    (earmark_parser 1.4.12) lib/earmark_parser/parser.ex:359: EarmarkParser.Parser._consolidate_para/3
    (earmark_parser 1.4.12) lib/earmark_parser/parser.ex:165: EarmarkParser.Parser._parse/4
    (earmark_parser 1.4.12) lib/earmark_parser/parser.ex:66: EarmarkParser.Parser.lines_to_blocks/3
    (earmark_parser 1.4.12) lib/earmark_parser/parser.ex:60: EarmarkParser.Parser.parse_lines/3
    (earmark_parser 1.4.12) lib/earmark_parser/parser.ex:26: EarmarkParser.Parser.parse_markdown/2

I tried updating to the latest version of Earmark available but got the following when running mix docs:

...

== Compilation error in file lib/Issues/github_Issues.ex ==
** (Protocol.UndefinedError) protocol Enumerable not implemented for :info of type Atom
    (elixir 1.11.2) lib/enum.ex:1: Enumerable.impl_for!/1
    (elixir 1.11.2) lib/enum.ex:141: Enumerable.reduce/3
    (elixir 1.11.2) lib/enum.ex:369: Enum.any?/2
    (logger 1.11.2) lib/logger.ex:1020: Logger.macro_log/4
    (logger 1.11.2) expanding macro: Logger.info/1
    lib/Issues/github_Issues.ex:11: Issues.GithubIssues.fetch/2

I can eliminate the last set of errors by commenting out the calls to Logger.debug and Logger.info.