ruby-debug-ideのインストールが失敗したときの対応

rubyを2.4.2に切り替えてbundleインストールし直してたらエラーに遭遇したのでその対応をメモ。

まずはrubyを2.4.2にアップデート。

```zsh
$ rbenv install 2.4.2
$ rbenv global 2.4.2
```

bundlerをインストールして、gemもインストール、、、ってところでエラった／(^o^)＼

```zsh
$ gem install bundler
$ bundle install
Fetching validates_timeliness 4.0.2
Installing validates_timeliness 4.0.2
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/ruby-debug-ide-0.6.0/ext
/Users/paranishian/.rbenv/versions/2.4.2/bin/ruby mkrf_conf.rb
/Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/2.4.0/rubygems/ext/builder.rb:76: warning: Insecure world writable dir /usr/local in PATH, mode 040757
Installing base gem
Building native extensions.  This could take a while...
Building native extensions.  This could take a while...
ERROR: Failed to build gem native extension.

（中略）

An error occurred while installing ruby-debug-ide (0.6.0), and Bundler cannot continue.
Make sure that `gem install ruby-debug-ide -v '0.6.0'` succeeds before bundling.

In Gemfile:
  ruby-debug-ide
```

# 対応手順

`ruby-debug-ide`がインストール失敗しちゃったので単発でインストールしてみる。

```zsh
$ gem install ruby-debug-ide -v '0.6.0'
Building native extensions.  This could take a while...
/Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/2.4.0/rubygems/ext/builder.rb:76: warning: Insecure world writable dir /usr/local in PATH, mode 040757
ERROR:  Error installing ruby-debug-ide:
        ERROR: Failed to build gem native extension.

（中略）

/Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/debase-ruby_core_source-0.9.7/lib/debase/ruby_core_source.rb:73:in `ruby_source_dir_version': undefined method `[]' for nil:NilClass (NoMethodError)
        from /Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/debase-ruby_core_source-0.9.7/lib/debase/ruby_core_source.rb:61:in `block in deduce_packaged_source_dir'
        from /Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/debase-ruby_core_source-0.9.7/lib/debase/ruby_core_source.rb:61:in `map'
        from /Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/debase-ruby_core_source-0.9.7/lib/debase/ruby_core_source.rb:61:in `deduce_packaged_source_dir'
        from /Users/paranishian/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/debase-ruby_core_source-0.9.7/lib/debase/ruby_core_source.rb:39:in `create_makefile_with_core'
        from extconf.rb:47:in `<main>'

To see why this extension failed to compile, please check the mkmf.log which can be found here:
```

なんだか`debase-ruby_core_source`でうまく動いてないっぽいのでアップデート。

```zsh
$ gem update debase-ruby_core_source
Updating installed gems
Updating debase-ruby_core_source
Fetching: debase-ruby_core_source-0.9.10.gem (100%)
Successfully installed debase-ruby_core_source-0.9.10
Parsing documentation for debase-ruby_core_source-0.9.10
Installing ri documentation for debase-ruby_core_source-0.9.10
Installing darkfish documentation for debase-ruby_core_source-0.9.10
Done installing documentation for debase-ruby_core_source after 41 seconds
Parsing documentation for debase-ruby_core_source-0.9.10
Done installing documentation for debase-ruby_core_source after 18 seconds
Gems updated: debase-ruby_core_source
```

もっかいbundle試してみる。

```zsh
$ bundle install
```

インストール成功！(^o^)