I just bought this book today and am having trouble getting the sample code running on an M1 MacBook.

I cd into chapter_01/02 do git init to save the initial state. Then I install Ruby 3.1.2 and run bundle install.

An error occurred while installing html_tokenizer (0.0.7), and Bundler cannot continue.

In Gemfile:
  erb_lint was resolved to 0.1.1, which depends on
    better_html was resolved to 1.0.16, which depends on
      html_tokenizer

$ ruby -v
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [arm64-darwin24]

Here’s the error log:

current directory: /Users/username/.rbenv/versions/3.1.2/lib/ruby/gems/3.1.0/gems/html_tokenizer-0.0.7/ext/html_tokenizer_ext
/Users/username/.rbenv/versions/3.1.2/bin/ruby -I /Users/username/.rbenv/versions/3.1.2/lib/ruby/3.1.0 -r ./siteconf20250429-32568-hbwjju.rb extconf.rb
creating Makefile

current directory: /Users/username/.rbenv/versions/3.1.2/lib/ruby/gems/3.1.0/gems/html_tokenizer-0.0.7/ext/html_tokenizer_ext
make DESTDIR\= clean

current directory: /Users/username/.rbenv/versions/3.1.2/lib/ruby/gems/3.1.0/gems/html_tokenizer-0.0.7/ext/html_tokenizer_ext
make DESTDIR\=
compiling html_tokenizer.c
compiling parser.c
parser.c:459:45: warning: implicit conversion loses integer precision: 'unsigned long' to 'int' [-Wshorten-64-to-32]
  459 |       INT2NUM(ref.line_number), INT2NUM(ref.column_number));
      |                                 ~~~~~~~ ~~~~^~~~~~~~~~~~~
parser.c:459:19: warning: implicit conversion loses integer precision: 'unsigned long' to 'int' [-Wshorten-64-to-32]
  459 |       INT2NUM(ref.line_number), INT2NUM(ref.column_number));
      |       ~~~~~~~ ~~~~^~~~~~~~~~~
parser.c:458:51: warning: implicit conversion loses integer precision: 'unsigned long' to 'int' [-Wshorten-64-to-32]
  458 |       INT2NUM(ref.mb_start), INT2NUM(ref.mb_start + mb_strlen),
      |                              ~~~~~~~ ~~~~~~~~~~~~~^~~~~~~~~~~
parser.c:458:19: warning: implicit conversion loses integer precision: 'unsigned long' to 'int' [-Wshorten-64-to-32]
  458 |       INT2NUM(ref.mb_start), INT2NUM(ref.mb_start + mb_strlen),
      |       ~~~~~~~ ~~~~^~~~~~~~
parser.c:498:9: warning: unused variable 'old' [-Wunused-variable]
  498 |   void *old = parser->doc.data;
      |         ^~~
parser.c:721:26: warning: implicit conversion loses integer precision: 'size_t' (aka 'unsigned long') to 'int' [-Wshorten-64-to-32]
  721 |   return INT2NUM(parser->errors_count);
      |          ~~~~~~~ ~~~~~~~~^~~~~~~~~~~~
parser.c:792:3: error: incompatible function pointer types passing 'VALUE (VALUE, VALUE)' (aka 'unsigned long (unsigned long, unsigned long)') to parameter of type 'VALUE (*)(VALUE)' (aka 'unsigned long (*)(unsigned long)') [-Wincompatible-function-pointer-types]
  792 |   rb_define_method(cParser, "errors", parser_errors_method, 0);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/username/.rbenv/versions/3.1.2/include/ruby-3.1.0/ruby/internal/anyargs.h:287:135: note: expanded from macro 'rb_define_method'
  287 | #define rb_define_method(klass, mid, func, arity)           RBIMPL_ANYARGS_DISPATCH_rb_define_method((arity), (func))((klass), (mid), (func), (arity))
      |                                                                                                                                       ^~~~~~
/Users/username/.rbenv/versions/3.1.2/include/ruby-3.1.0/ruby/internal/anyargs.h:276:1: note: passing argument to parameter here
  276 | RBIMPL_ANYARGS_DECL(rb_define_method, VALUE, const char *)
      | ^
/Users/username/.rbenv/versions/3.1.2/include/ruby-3.1.0/ruby/internal/anyargs.h:254:72: note: expanded from macro 'RBIMPL_ANYARGS_DECL'
  254 | RBIMPL_ANYARGS_ATTRSET(sym) static void sym ## _00(__VA_ARGS__, VALUE(*)(VALUE), int); \
      |                                                                        ^
6 warnings and 1 error generated.
make: *** [parser.o] Error 1

make failed, exit code 2

I spent almost an hour with Copilot trying to debug it, but still couldn’t get it to run. I updated some of the dependencies, but that just created other errors where it couldn’t find the Logger.

Has anyone been able to get the sample code working recently?