チュートリアル２章

2.1 アプリケーションの計画
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source 'https://rubygems.org'

gem 'rails', '5.0.3'
gem 'puma', '3.9.1'
gem 'sass-rails', '5.0.6'
gem 'uglifier', '3.2.0'
gem 'coffee-rails', '4.2.2'
gem 'jquery-rails', '4.3.1'
gem 'turbolinks', '5.0.1'
gem 'jbuilder', '2.7.0'

group :development, :test do
gem 'sqlite3', '1.3.13'
gem 'byebug', '9.0.6', platform: :mri
end

group :development do
gem 'web-console', '3.5.1'
gem 'listen', '3.0.8'
gem 'spring', '2.0.2'
gem 'spring-watcher-listen', '2.0.1'
end

group :production do
gem 'pg', '0.20.0'
end

Windows環境ではtzinfo-dataというgemを含める必要があります

gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

でbundle install --without production
するもエラー
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korosuke:~/workspace/toy_app $ bundle install --without production

[!] There was an error parsing Gemfile: You cannot specify the same gem twice with different version requirements.
You specified: sqlite3 (>= 0) and sqlite3 (= 1.3.13). Bundler cannot continue.

# from /home/ubuntu/workspace/toy_app/Gemfile:40
# -------------------------------------------
# # Call 'byebug' anywhere in the code to stop execution and get a debugger console

gem 'sqlite3', '1.3.13'
# gem 'byebug', '9.0.6', platform: :mri
# -------------------------------------------

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↓　解決策
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チュートリアルに書いてるgemfileをコピペして保存後に
bundle update

解決。