Fetching mysql2 0.3.21
Installing mysql2 0.3.21 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/mfifth/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/mysql2-0.3.21/ext/mysql2
/Users/mfifth/.rbenv/versions/2.5.1/bin/ruby -r ./siteconf20191213-16231-1j1qitw.rb extconf.rb --with-ldflags=-L/usr/local/opt/openssl/lib
--with-cppflags=-I/usr/local/opt/openssl/include
checking for ruby/thread.h... yes
checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
checking for rb_thread_blocking_region()... no
checking for rb_wait_for_single_fd()... yes
checking for rb_hash_dup()... yes
checking for rb_intern3()... yes
-----
Using mysql_config at /usr/local/bin/mysql_config
-----
checking for mysql.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
-----
Setting rpath to /usr/local/Cellar/mysql/8.0.18_1/lib
-----
creating Makefile

current directory: /Users/mfifth/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/mysql2-0.3.21/ext/mysql2
make "DESTDIR=" clean

current directory: /Users/mfifth/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/mysql2-0.3.21/ext/mysql2
make "DESTDIR="
compiling client.c
client.c:439:3: error: use of undeclared identifier 'my_bool'
  my_bool res = mysql_read_query_result(client);
  ^
client.c:441:19: error: use of undeclared identifier 'res'
  return (void *)(res == 0 ? Qtrue : Qfalse);
                  ^
client.c:762:3: error: use of undeclared identifier 'my_bool'
  my_bool boolval;
  ^
client.c:793:7: error: use of undeclared identifier 'boolval'
      boolval = (value == Qfalse ? 0 : 1);
      ^
client.c:794:17: error: use of undeclared identifier 'boolval'
      retval = &boolval;
                ^
client.c:797:10: error: use of undeclared identifier 'MYSQL_SECURE_AUTH'; did you mean 'MYSQL_DEFAULT_AUTH'?
    case MYSQL_SECURE_AUTH:
         ^~~~~~~~~~~~~~~~~
         MYSQL_DEFAULT_AUTH
/usr/local/Cellar/mysql/8.0.18_1/include/mysql/mysql.h:187:3: note: 'MYSQL_DEFAULT_AUTH' declared here
  MYSQL_DEFAULT_AUTH,
  ^
client.c:798:7: error: use of undeclared identifier 'boolval'
      boolval = (value == Qfalse ? 0 : 1);
      ^
client.c:799:17: error: use of undeclared identifier 'boolval'
      retval = &boolval;
                ^
client.c:830:38: error: use of undeclared identifier 'boolval'
        wrapper->reconnect_enabled = boolval;
                                     ^
client.c:1185:38: error: use of undeclared identifier 'MYSQL_SECURE_AUTH'; did you mean 'MYSQL_DEFAULT_AUTH'?
  return _mysql_client_options(self, MYSQL_SECURE_AUTH, value);
                                     ^~~~~~~~~~~~~~~~~
                                     MYSQL_DEFAULT_AUTH
/usr/local/Cellar/mysql/8.0.18_1/include/mysql/mysql.h:187:3: note: 'MYSQL_DEFAULT_AUTH' declared here
  MYSQL_DEFAULT_AUTH,
  ^
10 errors generated.
make: *** [client.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/mfifth/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/mysql2-0.3.21 for inspection.
Results logged to /Users/mfifth/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/extensions/x86_64-darwin-17/2.5.0-static/mysql2-0.3.21/gem_make.out

An error occurred while installing mysql2 (0.3.21), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.3.21' --source 'http://rubygems.org/'` succeeds before bundling.