Install mysql2 on MacOS Mojave

mysql2-mojave.md

For MacOS Catalina, visit Install mysql2 on MacOS Catalina

Problem

Installing mysql2 gem errors on MacOS Mojave.

Solution

Make sure openssl is installed on Mac via Homebrew.

brew install openssl

Install mysql2 gem.

gem install mysql2 -v '0.5.2' -- --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include

Thanks, man!

Heroic

Yaasss!

If you came here because you're trying to bundle your project into a specific directory and the gem won't build, you can tell bundler to use these build flags when it installs the gem.

bundle config build.mysql2 --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include
bundle install --path .bundle

Thanks!

Thank you so much! You were a big help!

took me an hour until I finally found your solution, thanks!

save my life

I still get this error:

cannot load such file -- mysql2/mysql2

when trying to use mysql2 on Rails (5.2.2)

Works on my machine!

Just found this, and it was immensely helpful. How did you reach this solution?

excellent, thanks!

Hurray!!! That did it!
Thank you!

Thank you!

Much appreciated!

Thanks!

ありがとう！

You the man!

Thanks!

🥇

Thank you, just saved me quite some time!

Thanks a lot man! I was seriously getting crazy!

Thanks a lot man. Been on it for an hour!!

I have this in ~/.bundle/config:

BUNDLE_BUILD__NOKOGIRI: "--use-system-libraries --with-xml2-include=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/libxml2/"
BUNDLE_BUILD__MYSQL2: "--with-ldflags=-L/usr/local/opt/openssl@1.1/lib --with-cppflags=-I/usr/local/opt/openssl@1.1/include"

This worked for me:

bundle config build.mysql2 --with-opt-dir=/usr/local/opt/openssl

thanks bro, saved me loads of time

I got here because I got don't know how to set rpath on your system error initially. Upon googling you'll reach this SO thread which only details either installing / reinstalling openssl but since I already did this and all other configuration options mentioned were outdated for me, this wasn't very useful. Only after fiddling with many different configuration options, none of which worked, this actually got it to work for me.

It really does suck that the combination of mysql+brew+macos seems to break with every OS update, though :(

macOS 10.14.3
fish 3.0.1
openssl 1.0.2r

With all that being said, thanks a lot, you saved me some good amount of time as well!

that fixed building eventmachine too for me:

gem install eventmachine -v '1.2.7' --source 'https://rubygems.org/' -- --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include

This will fix your issue while bundle.
gem install mysql2 -v '0.3.21' -- --with-mysql-config=/usr/local/bin/mysql_config --srcdir=/usr/local/include/mysql/ --platform=ruby --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include

Still looking resolution for `require': cannot load such file -- mysql2/mysql2 (LoadError) while running command rails s.

thanks man!

This helped me when the gem install kept on errorring out about not being able to find the mysql client... I modified @AnshulRiyal's command a little:

On Mojave, High Sierra, or Catalina, using homebrew.

gem install mysql2 -v 'YOUR.VERSION.HERE' -- --with-mysql-config=/usr/local/opt/mysql-client/bin/mysql_config \
                 --srcdir=/usr/local/opt/mysql/include --platform=ruby \
                 --with-ldflags=-L/usr/local/opt/openssl/lib \
                 --with-cppflags=-I/usr/local/opt/openssl/include

i have taken one all day for this problem
awesome! thanks!!

My hero man, thank you.

You are the bestest! Thank you

I only seemed to need bundle config build.mysql2 --with-ldflags=-L/usr/local/opt/openssl/lib. When I used bundle config build.mysql2 --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include, I got the following error:

Fetching mysql2 0.5.2
Installing mysql2 0.5.2 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/dale/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/mysql2-0.5.2/ext/mysql2
/Users/dale/.rbenv/versions/2.6.2/bin/ruby -I /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0 -r ./siteconf20190525-54468-194taa7.rb extconf.rb
--with-ldflags\=-L/usr/local/opt/openssl/lib\ --with-cppflags\=-I/usr/local/opt/openssl/include
checking for rb_absint_size()... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/Users/dale/.rbenv/versions/2.6.2/bin/$(RUBY_BASE_NAME)
/Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:467:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:552:in `try_link0'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:570:in `try_link'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:782:in `try_func'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:1069:in `block in have_func'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:959:in `block in checking_for'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:361:in `block (2 levels) in postpone'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:331:in `open'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:361:in `block in postpone'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:331:in `open'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:357:in `postpone'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:958:in `checking_for'
	from /Users/dale/.rbenv/versions/2.6.2/lib/ruby/2.6.0/mkmf.rb:1068:in `have_func'
	from extconf.rb:25:in `<main>'

Brilliant!

Thanks!

This worked for me:

bundle config build.mysql2 --with-opt-dir=/usr/local/opt/openssl

THX. Works for me.

bundle config build.mysql2 --with-opt-dir=/usr/local/opt/openssl
bundle install

Great!

2019 still actual
Thanks!)

Mojave 10.14.4
Not all heros wear capes thanks.

This worked:

bundle config build.mysql2 --with-opt-dir=/usr/local/opt/openssl
bundle install

hero !!!

savior!

my hero!!!

Thank you

Thank you!

Thank you!

Thank you!
But seems that doesn't work for macOS Mojave 10.14.5 with gem 'mysql2', '0.3.18'. I got this error:

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
/Users/user/.rvm/rubies/ruby-2.3.0/bin/ruby -I /Users/user/.rvm/rubies/ruby-2.3.0/lib/ruby/site_ruby/2.3.0 -r ./siteconf20190729-60037-dvrkxr.rb extconf.rb
--with-opt-dir\=/usr/local/opt/openssl
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/8.0.16/lib
-----
creating Makefile

current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
make "DESTDIR=" clean

current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
make "DESTDIR="
compiling infile.c
compiling client.c
client.c:359:33: warning: implicit conversion loses integer precision: 'long' to 'unsigned int' [-Wshorten-64-to-32]
        elapsed_time = end_time - start_time;
                     ~ ~~~~~~~~~^~~~~~~~~~~~
client.c:431:3: error: use of undeclared identifier 'my_bool'
  my_bool res = mysql_read_query_result(client);
  ^
client.c:433:19: 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/8.0.16/include/mysql/mysql.h:188:3: 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:1163:56: warning: implicit conversion loses integer precision: 'size_t' (aka 'unsigned long') to 'unsigned int' [-Wshorten-64-to-32]
  mysql2rb = mysql2_mysql_enc_name_to_rb(charset_name, charset_name_len);
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~               ^~~~~~~~~~~~~~~~
client.c:1196:38: 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/8.0.16/include/mysql/mysql.h:188:3: note: 'MYSQL_DEFAULT_AUTH' declared here
  MYSQL_DEFAULT_AUTH,
  ^
2 warnings and 10 errors generated.
make: *** [client.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18 for inspection.
Results logged to /Users/user/.rvm/gems/ruby-2.3.0/extensions/x86_64-darwin-18/2.3.0/mysql2-0.3.18/gem_make.out

An error occurred while installing mysql2 (0.3.18), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.3.18' --source 'https://rubygems.org/'` succeeds before bundling.

In Gemfile:
  mysql2

Thanks!

thank you!!!

Thanks so much for this!

@HugApps, @swarup98, @RCheesley you're welcome. Glad it helped. 👍

Great thanks man

thanks 💯

Nice.

I also ran this as sudo to get access to the global libraries. Thanks!!

Oh wow, thank you for this!!! Saved my day!

Nice, Thanks for this!

This works!

Thanx!

🎉

You saved my day! Thanx!!

Sooo good! Thanks!

A true hero

👍

Thanks a lot!!!!!!!!!

macOS Catalina also works.

Thank you! 🙏 💯

Thanks a lot!!!!!!!!!

Thanks a lot!

Hey there! i'm having same issue on Mac os catalina. Tried all possible solutions reported here , still getting error after trying to do bundle.
Error

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

 /Users/hernangimenez/.rbenv/versions/2.1.4/bin/ruby 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()... yes
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

make "DESTDIR=" clean

make "DESTDIR="
compiling infile.c
compiling client.c
client.c:359:33: warning: implicit conversion loses integer precision: 'long' to 'unsigned int' [-Wshorten-64-to-32]
        elapsed_time = end_time - start_time;
                     ~ ~~~~~~~~~^~~~~~~~~~~~
client.c:431:3: error: use of undeclared identifier 'my_bool'
  my_bool res = mysql_read_query_result(client);
  ^
client.c:433:19: 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:1163:56: warning: implicit conversion loses integer precision: 'size_t' (aka 'unsigned long') to 'unsigned int' [-Wshorten-64-to-32]
  mysql2rb = mysql2_mysql_enc_name_to_rb(charset_name, charset_name_len);
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~               ^~~~~~~~~~~~~~~~
client.c:1196:38: 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,
  ^
2 warnings and 10 errors generated.
make: *** [client.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/hernangimenez/Desktop/proyectos/osdipp/osdipp/vendor/bundle/ruby/2.1.0/gems/mysql2-0.2.24 for inspection.
Results logged to /Users/hernangimenez/Desktop/proyectos/osdipp/osdipp/vendor/bundle/ruby/2.1.0/extensions/x86_64-darwin-19/2.1.0-static/mysql2-0.2.24/gem_make.out

An error occurred while installing mysql2 (0.2.24), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.2.24' --source 'http://rubygems.org/'` succeeds before bundling.

In Gemfile:
  mysql2 

Then tried

Hernans-MacBook-Pro-2:osdipp hernangimenez$ gem install mysql2 -v '0.2.24' --source 'http://rubygems.org/'
ERROR:  While executing gem ... (Errno::EACCES)
    Permission denied @ rb_sysopen - /Users/hernangimenez/.rbenv/versions/2.1.4/lib/ruby/gems/2.1.0/gems/mysql2-0.2.24/MIT-LICENSE
Hernans-MacBook-Pro-2:osdipp hernangimenez$ 

any help?

Thank you!!!!

Thanks!
Slightly cuter to ask brew where openssl is: gem install mysql2 -- --with-opt-dir=$(brew --prefix openssl)

thank you, this help me a lots

Just got a new macOS 16 inches Catalina from scratch. Build failed because I forgot to install MySQL. After issue brew install mysql the options offered above works 🙏 💯🙏 💯🙏 💯.

Super helpful, thanks!

If you were a Witcher, I'd definitely toss a coin to you. Thanks dude! This was very helpful.

If you were a Witcher, I'd definitely toss a coin to you

@thnery HA, thanks and you're welcome. 😃

This worked for me:

bundle config build.mysql2 --with-opt-dir=/usr/local/opt/openssl

THX 👍

When I installed mysql2 with ruby-2.3.8 I had to use both ldflags and cppflags opts:

bundle config build.mysql2 --with-ldflags=-L/usr/local/opt/openssl@1.1/lib --with-cppflags=-I/usr/local/opt/openssl@1.1/include --with-opt-dir=/usr/local/opt/openssl@1.1

However, when I migrate my app to ruby-2.6.5, the above is stopped to work. So, I had to change it by only --with-opt-dir opt:

bundle config build.mysql2 --with-opt-dir=/usr/local/opt/openssl@1.1

or simpler:

bundle config build.mysql2 --with-opt-dir=$(brew --prefix openssl)

Thanks

Thanks!!!!

or simpler:

bundle config build.mysql2 --with-opt-dir=$(brew --prefix openssl)

This was the winner for me on Catalina, thank you!

thanks!

or simpler:

bundle config build.mysql2 --with-opt-dir=$(brew --prefix openssl)

This was the winner for me on Catalina, thank you!

This was the only one that worked for me on Catalina!

Thank you!
But seems that doesn't work for macOS Mojave 10.14.5 with gem 'mysql2', '0.3.18'. I got this error:

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
/Users/user/.rvm/rubies/ruby-2.3.0/bin/ruby -I /Users/user/.rvm/rubies/ruby-2.3.0/lib/ruby/site_ruby/2.3.0 -r ./siteconf20190729-60037-dvrkxr.rb extconf.rb
--with-opt-dir\=/usr/local/opt/openssl
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/8.0.16/lib
-----
creating Makefile

current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
make "DESTDIR=" clean

current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
make "DESTDIR="
compiling infile.c
compiling client.c
client.c:359:33: warning: implicit conversion loses integer precision: 'long' to 'unsigned int' [-Wshorten-64-to-32]
        elapsed_time = end_time - start_time;
                     ~ ~~~~~~~~~^~~~~~~~~~~~
client.c:431:3: error: use of undeclared identifier 'my_bool'
  my_bool res = mysql_read_query_result(client);
  ^
client.c:433:19: 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/8.0.16/include/mysql/mysql.h:188:3: 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:1163:56: warning: implicit conversion loses integer precision: 'size_t' (aka 'unsigned long') to 'unsigned int' [-Wshorten-64-to-32]
  mysql2rb = mysql2_mysql_enc_name_to_rb(charset_name, charset_name_len);
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~               ^~~~~~~~~~~~~~~~
client.c:1196:38: 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/8.0.16/include/mysql/mysql.h:188:3: note: 'MYSQL_DEFAULT_AUTH' declared here
  MYSQL_DEFAULT_AUTH,
  ^
2 warnings and 10 errors generated.
make: *** [client.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18 for inspection.
Results logged to /Users/user/.rvm/gems/ruby-2.3.0/extensions/x86_64-darwin-18/2.3.0/mysql2-0.3.18/gem_make.out

An error occurred while installing mysql2 (0.3.18), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.3.18' --source 'https://rubygems.org/'` succeeds before bundling.

In Gemfile:
  mysql2

Getting same issue

Thank you!

I guess this is still open? Having same issues as everyone above. @fuadkhan1996 Did you find a solution? I'm on a new mac with an ol rails app I need to maitain and this is preventing me... Newer 0.5 mysql2 installs fine. But have tried everything above and still get the same error you get... frustrating... And I know the sky is falling, but would greatly appreciate anyone who has an insight into this...

Works. Thank you

Thank u!

Thank you so much.

I also needed to run this:

bundle config build.mysql2 --with-opt-dir=/usr/local/opt/openssl

And then:

bundle install

Saved my day! 😄

Thank you sir!

Thank you! This problem wasted so much time.

Worked on Catalina as well 10.15.4.
Thanks

Thank you so much for saving me hours.

Thank this work on macOS Mojave 10.14.5

Thank you so much! This worked for me on macOS Catalina 10.15.3

Thank you so much!!!

Every year, tracking down the same failures...

Thank you 👍

Thank you, you made my day.

Thanks a lot ! it worked

Bookmarking this has saved me multiple times. Thank you!

thanks. I keep finding this page again and again

thanks a lot

bundle config build.mysql2 --with-opt-dir=$(brew --prefix openssl)

fixed my ld: library not found for -lssl error, because homebrew only had openssl@1.1 installed

bundle config build.mysql2 --with-opt-dir=$(brew --prefix openssl)

fixed my ld: library not found for -lssl error, because homebrew only had openssl@1.1 installed

👍

Thank you, E. Sambo! It works!

@gee-forr thank you!

Thank you!!

Thank you!
But seems that doesn't work for macOS Mojave 10.14.5 with gem 'mysql2', '0.3.18'. I got this error:

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
/Users/user/.rvm/rubies/ruby-2.3.0/bin/ruby -I /Users/user/.rvm/rubies/ruby-2.3.0/lib/ruby/site_ruby/2.3.0 -r ./siteconf20190729-60037-dvrkxr.rb extconf.rb
--with-opt-dir\=/usr/local/opt/openssl
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/8.0.16/lib
-----
creating Makefile

current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
make "DESTDIR=" clean

current directory: /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18/ext/mysql2
make "DESTDIR="
compiling infile.c
compiling client.c
client.c:359:33: warning: implicit conversion loses integer precision: 'long' to 'unsigned int' [-Wshorten-64-to-32]
        elapsed_time = end_time - start_time;
                     ~ ~~~~~~~~~^~~~~~~~~~~~
client.c:431:3: error: use of undeclared identifier 'my_bool'
  my_bool res = mysql_read_query_result(client);
  ^
client.c:433:19: 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/8.0.16/include/mysql/mysql.h:188:3: 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:1163:56: warning: implicit conversion loses integer precision: 'size_t' (aka 'unsigned long') to 'unsigned int' [-Wshorten-64-to-32]
  mysql2rb = mysql2_mysql_enc_name_to_rb(charset_name, charset_name_len);
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~               ^~~~~~~~~~~~~~~~
client.c:1196:38: 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/8.0.16/include/mysql/mysql.h:188:3: note: 'MYSQL_DEFAULT_AUTH' declared here
  MYSQL_DEFAULT_AUTH,
  ^
2 warnings and 10 errors generated.
make: *** [client.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/user/.rvm/gems/ruby-2.3.0/gems/mysql2-0.3.18 for inspection.
Results logged to /Users/user/.rvm/gems/ruby-2.3.0/extensions/x86_64-darwin-18/2.3.0/mysql2-0.3.18/gem_make.out

An error occurred while installing mysql2 (0.3.18), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.3.18' --source 'https://rubygems.org/'` succeeds before bundling.

In Gemfile:
  mysql2

Getting same issue

I am having the same issue...

Nice!!!

Life saver!

Still works using mysql2 0.5.3

As of today Homebrew defaults to MySQL 8.0, OpenSSL 1.1 and mysql2 0.5 that work great all together out of the box. However to upgrade of my legacy applications from Rails 3.2 to more recent versions I had to setup local environment on my MacOS BigSur 11.1.

My goal was to install mysql2 gem version 0.3.x (this is only one allowing smooth migration from Rails 3.2 to Rails 4.2 through versions 4.0 and 4.1) together with mySQL 5.x. Both of them in turn depend on OpenSSL 1.0

Here is what worked for me:

// Clean-up all your faulty attempts you did before
// Homebrew does not store openssl 1.0 anymore, so I had to find alternative — openssl1.0.2t 
wget https://github.com/tebelorg/Tump/releases/download/v1.0.0/openssl.rb
brew install openssl.rb

brew install mysql@5.7
brew link mysql@5.7 --force
brew install mysql-client@5.7
// NB! Pay close attention to path where you have mysql_config and openssl 1.0 installed
gem install mysql2 -v 0.3.21 -- --with-mysql-config=/usr/local/bin/mysql_config --with-ldflags=-L/usr/local/Cellar/openssl/1.0.2t/lib --with-cppflags=-I/usr/local/Cellar/openssl/1.0.2t/include

Voilá:

Building native extensions with: '--with-mysql-config=/usr/local/bin/mysql_config --with-ldflags=-L/usr/local/Cellar/openssl/1.0.2t/lib --with-cppflags=-I/usr/local/Cellar/openssl/1.0.2t/include'
This could take a while...
Successfully installed mysql2-0.3.21
Parsing documentation for mysql2-0.3.21
Installing ri documentation for mysql2-0.3.21
Done installing documentation for mysql2 after 0 seconds
1 gem installed

As of today Homebrew defaults to MySQL 8.0, OpenSSL 1.1 and mysql2 0.5 that work great all together out of the box. However to upgrade of my legacy applications from Rails 3.2 to more recent versions I had to setup local environment on my MacOS BigSur 11.1.

My goal was to install mysql2 gem version 0.3.x (this is only one allowing smooth migration from Rails 3.2 to Rails 4.2 through versions 4.0 and 4.1) together with mySQL 5.x. Both of them in turn depend on OpenSSL 1.0

Here is what worked for me:

// Clean-up all your faulty attempts you did before
// Homebrew does not store openssl 1.0 anymore, so I had to find alternative — openssl1.0.2t 
wget https://github.com/tebelorg/Tump/releases/download/v1.0.0/openssl.rb
brew install openssl.rb

brew install mysql@5.7
brew link mysql@5.7 --force
brew install mysql-client@5.7
// NB! Pay close attention to path where you have mysql_config and openssl 1.0 installed
gem install mysql2 -v 0.3.21 -- --with-mysql-config=/usr/local/bin/mysql_config --with-ldflags=-L/usr/local/Cellar/openssl/1.0.2t/lib --with-cppflags=-I/usr/local/Cellar/openssl/1.0.2t/include

Voilá:

Building native extensions with: '--with-mysql-config=/usr/local/bin/mysql_config --with-ldflags=-L/usr/local/Cellar/openssl/1.0.2t/lib --with-cppflags=-I/usr/local/Cellar/openssl/1.0.2t/include'
This could take a while...
Successfully installed mysql2-0.3.21
Parsing documentation for mysql2-0.3.21
Installing ri documentation for mysql2-0.3.21
Done installing documentation for mysql2 after 0 seconds
1 gem installed

Thanks a lot Bro. Saved my day!

thanks, it works

bundle config build.mysql2 --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include
bundle install --path .bundle

@mgoggin Thank you for this!! This is what I needed.