gem install mysql2 Building native extensions. This could take a while... ERROR: Error installing mysql2: ERROR: Failed to build gem native extension. /Users/frank/.rbenv/versions/2.2.4/bin/ruby -r ./siteconf20161017-40878-1pj8mbn.rb extconf.rb 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 ----- Don't 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/mariadb/10.1.18/lib ----- creating Makefile make "DESTDIR=" clean 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/frank/.rbenv/versions/2.2.4/lib/ruby/gems/2.2.0/gems/mysql2-0.4.4 for inspection. Results logged to /Users/frank/.rbenv/versions/2.2.4/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-16/2.2.0-static/mysql2-0.4.4/gem_make.out