gem file

Bundle edge Rails instead: gem 'rails', github: 'rails/rails'

gem 'rails', '~> 5.1.4'

Use mysql as the database for Active Record

gem 'mysql2', '>= 0.3.18', '< 0.5'

ターミナル
Fetching mysql2 0.4.10
Installing mysql2 0.4.10 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

省略...

Gem files will remain installed in
/Users/makmzw/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mysql2-0.4.10 for inspection.
Results logged to
/Users/makmzw/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-16/2.3.0-static/mysql2-0.4.10/gem_make.out

An error occurred while installing mysql2 (0.4.10), and Bundler cannot continue.
Make sure that gem install mysql2 -v '0.4.10' succeeds before bundling.

In Gemfile:
mysql2

変更後：
gem 'mysql2', '>= 0.4.10', '< 0.5'

ターミナル:
bundle install

同様のエラーが出ます。

An error occurred while installing mysql2 (0.4.10), and Bundler cannot continue.
Make sure that gem install mysql2 -v '0.4.10' succeeds before bundling.

行動規範の内容に同意します

回答3件

一度アンインストールし直しました。

投稿2018/05/21 21:46

black-to

総合スコア18

自己解決

パスが通っていませんでした。

投稿2018/05/21 21:45

black-to

総合スコア18

類似の症状がいくつか検索に引っかかります

これを見るとあなたが省略した部分が必要な情報に思われます。

まずはエラーメッセージの指示通りに
gem install mysql2 -v '0.4.10'コマンドを実行して
どういうエラーが出るのかを確認しましょう。

また、mysql"ライブラリ"はインストールされているかを確認すべきでしょう

投稿2018/05/20 09:32

asm

総合スコア15147

black-to

2018/05/20 14:16

ありがとうございます。 brew install mysql' 実行済みです。 or 'port install mysql' port install mysql -bash: port: command not foundと表示されます。 sudo gem install mysql2 -v '0.4.10' Password: Building native extensions. This could take a while... ERROR: Error installing mysql2: ERROR: Failed to build gem native extension. current directory: /Users/***/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mysql2-0.4.10/ext/mysql2 /Users/***/.rbenv/versions/2.3.1/bin/ruby -r ./siteconf20180520-7497-n9yd5m.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 checking for mysql_query() in -lmysqlclient... no ----- mysql client is missing. You may need to 'brew install mysql' or 'port install mysql', and try again. ----- *** 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/***/.rbenv/versions/2.3.1/bin/$(RUBY_BASE_NAME) --with-mysql-dir --without-mysql-dir --with-mysql-include --without-mysql-include=${mysql-dir}/include --with-mysql-lib --without-mysql-lib=${mysql-dir}/lib --with-mysql-config --without-mysql-config --with-mysql-dir --without-mysql-dir --with-mysql-include --without-mysql-include=${mysql-dir}/include --with-mysql-lib --without-mysql-lib=${mysql-dir}/lib --with-mysqlclientlib --without-mysqlclientlib To see why this extension failed to compile, please check the mkmf.log which can be found here: /Users/***/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-16/2.3.0-static/mysql2-0.4.10/mkmf.log extconf failed, exit code 1 Gem files will remain installed in /Users/***/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mysql2-0.4.10 for inspection. Results logged to /Users/***/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-16/2.3.0-static/mysql2-0.4.10/gem_make.out