Error to bundle install "yajl-ruby"

Question

noob here, I'm trying to install octopress but when i run rbenv exec bundle install i got this error.

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
current directory:
/home/idiot/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/yajl-ruby-1.2.1/ext/yajl
/home/idiot/.rbenv/versions/2.4.0/bin/ruby -r ./siteconf20170227-4161-uizrqn.rb extconf.rb
creating Makefile

current directory:
/home/idiot/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/yajl-ruby-1.2.1/ext/yajl
make "DESTDIR=" clean

current directory:
/home/idiot/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/yajl-ruby-1.2.1/ext/yajl
make "DESTDIR="
compiling yajl.c
compiling yajl_alloc.c
compiling yajl_buf.c
compiling yajl_encode.c
compiling yajl_ext.c
yajl_ext.c: In function ‘rb_yajl_parser_parse’:
yajl_ext.c:471:17: warning: variable ‘stat’ set but not used [Wunused-but-set-variable]
yajl_status stat;
             ^~~~
yajl_ext.c: In function ‘rb_yajl_encoder_enable_json_gem_ext’:
yajl_ext.c:881:22: error: ‘rb_cFixnum’ undeclared (first use in this function)
rb_define_method(rb_cFixnum, "to_json", rb_yajl_json_ext_fixnum_to_json, -1);
                  ^~~~~~~~~~
yajl_ext.c:881:22: note: each undeclared identifier is reported only once for each
function it appears in
yajl_ext.c: At top level:
cc1: warning: unrecognized command line option ‘-Wno-self-assign’
cc1: warning: unrecognized command line option ‘-Wno-constant-logical-operand’
cc1: warning: unrecognized command line option ‘-Wno-parentheses-equality’
make: *** [Makefile:242: yajl_ext.o] Error 1

make failed, exit code 2

Gem files will remain installed in
/home/idiot/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/yajl-ruby1.2.1 for inspection.
Results logged to
  /home/idiot/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/extensions/x86_64-linux/2.4.0-static/yajl-ruby-1.2.1/gem_make.out

An error occurred while installing yajl-ruby (1.2.1), and Bundler cannot
continue.
Make sure that `gem install yajl-ruby -v '1.2.1'` succeeds before bundling.

I've tried to googling but still have not found a solution to this problem, anyone answer my question, I am very grateful.

Answer 1

The native extension has not been updated for Ruby 2.4 yet. The breaking change is that Fixnum and Bignum (rb_cFixnum and rb_cBignum in the C API) have been unified in Integer (rb_cInteger).

Check the yajl-ruby repository for an issue/pull request fixing Ruby 2.4 compatibility or use Ruby 2.3.3 for the time being.