結論
以下のようにして bundle install します。
$ bundle config --local build.mysql2 "--with-ldflags=-L/usr/local/opt/openssl/lib" $ bundle install
注意点
$ bundle config --local build.mysql2 "--with-ldflags=-L/usr/local/opt/openssl/lib"を実行しても、グローバルな環境は汚しません。.bundle/を削除すれば元通りです- 環境によっては、上記の内容で解決しない場合もあります
- MySQL 8 であることが原因です
エラーメッセージ詳細
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/foobar/hoge/vendor/bundle/ruby/2.6.0/gems/mysql2-0.5.2/ext/mysql2 /Users/foobar/.rbenv/versions/2.6.3/bin/ruby -I /Users/foobar/.rbenv/versions/2.6.3/lib/ruby/2.6.0 -r ./siteconf20190921-46990-10ddhny.rb extconf.rb checking for rb_absint_size()... yes checking for rb_absint_singlebit_p()... yes checking for rb_wait_for_single_fd()... yes ----- Using mysql_config at /usr/local/bin/mysql_config ----- checking for mysql.h... yes checking for errmsg.h... yes checking for SSL_MODE_DISABLED in mysql.h... yes checking for SSL_MODE_PREFERRED in mysql.h... yes checking for SSL_MODE_REQUIRED in mysql.h... yes checking for SSL_MODE_VERIFY_CA in mysql.h... yes checking for SSL_MODE_VERIFY_IDENTITY in mysql.h... yes checking for MYSQL.net.vio in mysql.h... yes checking for MYSQL.net.pvio in mysql.h... no checking for MYSQL_ENABLE_CLEARTEXT_PLUGIN in mysql.h... yes checking for SERVER_QUERY_NO_GOOD_INDEX_USED in mysql.h... yes checking for SERVER_QUERY_NO_INDEX_USED in mysql.h... yes checking for SERVER_QUERY_WAS_SLOW in mysql.h... yes checking for MYSQL_OPTION_MULTI_STATEMENTS_ON in mysql.h... yes checking for MYSQL_OPTION_MULTI_STATEMENTS_OFF in mysql.h... yes checking for my_bool in mysql.h... no ----- 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/mysql/8.0.17/lib ----- creating Makefile current directory: /Users/foobar/hoge/vendor/bundle/ruby/2.6.0/gems/mysql2-0.5.2/ext/mysql2 make "DESTDIR=" clean current directory: /Users/foobar/hoge/vendor/bundle/ruby/2.6.0/gems/mysql2-0.5.2/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/foobar/hoge/vendor/bundle/ruby/2.6.0/gems/mysql2-0.5.2 for inspection. Results logged to /Users/foobar/hoge/vendor/bundle/ruby/2.6.0/extensions/x86_64-darwin-18/2.6.0-static/mysql2-0.5.2/gem_make.out An error occurred while installing mysql2 (0.5.2), and Bundler cannot continue. Make sure that `gem install mysql2 -v '0.5.2' --source 'https://rubygems.org/'` succeeds before bundling. In Gemfile: mysql2
