新たな Web アプリを作ろうと Rails で Web サイトの設定をしていた際、bundle install 時に mysql2 のインストールが出来ないという感じのメッセージが出てコケた。
$ bundle install
(省略)
Installing mysql2 0.4.6 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/Users/ryomatsu/.rbenv/versions/2.2.3/bin/ruby -r ./siteconf20170522-17383-1e6hi2q.rb extconf.rb
checking for rb_absint_size()... yes
checking for rb_absint_singlebit_p()... yes
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
checking for rb_big_cmp()... yes
-----
Using mysql_config at /usr/local/bin//mysql_config
-----
checking for mysql.h... yes
checking for SSL_MODE_DISABLED in mysql.h... no
checking for MYSQL_OPT_SSL_ENFORCE in mysql.h... no
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/mysql/5.6.26/lib
-----
creating Makefile
make "DESTDIR=" clean
make "DESTDIR="
compiling client.c
compiling infile.c
compiling mysql2_ext.c
compiling result.c
result.c:326:40: warning: incompatible pointer types assigning to 'my_bool *' (aka 'char *') from 'bool *' [-Wincompatible-pointer-types]
wrapper->result_buffers[i].is_null = &wrapper->is_null[i];
^ ~~~~~~~~~~~~~~~~~~~~
result.c:328:40: warning: incompatible pointer types assigning to 'my_bool *' (aka 'char *') from 'bool *' [-Wincompatible-pointer-types]
wrapper->result_buffers[i].error = &wrapper->error[i];
^ ~~~~~~~~~~~~~~~~~~
2 warnings generated.
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/ryomatsu/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/mysql2-0.4.6 for inspection.
Results logged to /Users/ryomatsu/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-15/2.2.0-static/mysql2-0.4.6/gem_make.out
An error occurred while installing mysql2 (0.4.6), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.4.6'` succeeds before bundling.
エラーメッセージの下部にあるように gem install mysql2 -v '0.4.6' を実行してみるも以下のようにほぼ同じようなエラーメッセージが出て失敗した。
$ gem install mysql2 -v '0.4.6'
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.
(省略)
make failed, exit code 2
Gem files will remain installed in /Users/ryomatsu/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/mysql2-0.4.6 for inspection.
Results logged to /Users/ryomatsu/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-15/2.2.0-static/mysql2-0.4.6/gem_make.out
ググったらところ、Xcode のコマンドラインツールをインストールすると直るみたいな記述を発見したので試しにやってみたところ、mysql2 のインストールに成功した。
http://qiita.com/nakki/items/e15c6b024d27edb2b96b以下のコマンドを実行した後に・・・
$ xcode-select --install
bundle install を再度実行する。
$ bundle install
Using libv8 3.16.14.19
Using memoizable 0.4.2
Installing mysql2 0.4.6 with native extensions
Using naught 1.1.0
Installing oauth 0.5.2
Installing omniauth 1.6.1
これで開発に入れる。