Can't install mysql2 gem on macOS Sierra

Question

I'm setting up my development environment in the new macOS Sierra .

First of all, I installed Rbenv, Ruby (2.3.1), Homebrew and so the latest version of MySQL (5.7.15).

$ brew install mysql $ mysql.server start 

Ok, MySQL was initialized. Time to install the mysql2 gem...

$ gem install mysql2 -- --with-mysql-config=/usr/local/Cellar/mysql/5.7.15/bin/mysql_config 

But it didn't work. 😞

---

Building native extensions with: '--with-mysql-config=/usr/local/Cellar/mysql/5.7.15/bin/mysql_config' This could take a while... ERROR:  Error installing mysql2:     ERROR: Failed to build gem native extension.      current directory: /Users/macuser/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mysql2-0.4.4/ext/mysql2 /Users/macuser/.rbenv/versions/2.3.1/bin/ruby -r ./siteconf20160921-16853-x1boio.rb extconf.rb --with-mysql-config=/usr/local/Cellar/mysql/5.7.15/bin/mysql_config 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/Cellar/mysql/5.7.15/bin/mysql_config ----- checking for mysql.h... yes checking for errmsg.h... yes checking for mysqld_error.h... yes ----- Dont know how to set rpath on your system, if MySQL libraries are not in path mysql2 may not load ----- ----- Setting libpath to /usr/local/Cellar/mysql/5.7.15/lib ----- creating Makefile  To see why this extension failed to compile, please check the mkmf.log which can be found here:    /Users/macuser/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-16/2.3.0-static/mysql2-0.4.4/mkmf.log  current directory: /Users/macuser/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mysql2-0.4.4/ext/mysql2 make "DESTDIR=" clean  current directory: /Users/macuser/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mysql2-0.4.4/ext/mysql2 make "DESTDIR=" compiling client.c compiling infile.c compiling mysql2_ext.c compiling result.c compiling statement.c linking shared-object mysql2/mysql2.bundle ld: library not found for -lssl clang: error: linker command failed with exit code 1 (use -v to see invocation) make: *** [mysql2.bundle] Error 1  make failed, exit code 2  Gem files will remain installed in /Users/macuser/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mysql2-0.4.4 for inspection. Results logged to /Users/macuser/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-16/2.3.0-static/mysql2-0.4.4/gem_make.out 

Answer 1

I just had the same problem, tried all of the solutions listed above, then commenced to bang my head against they keyboard for a couple of hours.

I then thought to try and install/reinstall the Xcode Command Line Tools:

xcode-select --install 

Once I did that the mysql2 gem installed w/ no problems. I hope that does the trick!

Answer 2

When you install openssl via brew, you should get the following message:

Apple has deprecated use of OpenSSL in favor of its own TLS and crypto libraries

Generally there are no consequences of this for you. If you build your own software and it requires this formula, you'll need to add to your build variables:

LDFLAGS: -L/usr/local/opt/openssl/lib
CPPFLAGS: -I/usr/local/opt/openssl/include
PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig

You can set these build flags (for the local application) by running the following:

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

This worked for me.

See bundler's documentation for more information.