railsサーバが起動できません

###前提・実現したいこと
数時間前にした質問に関して、進展があったのでそれに関する質問です。現場で使えるRuby on rails 5 速習実践ガイドchapter3を参考にアプリケーションのひな型を作成したのですが、一度シャットダウンして次の日にもう一度bin/rails sで立ち上げようとしたら、下記のようなエラーが出ました。

###発生している問題・エラーメッセージ1

Traceback (most recent call last):
22: from bin/rails:3:in <main>'
21: from bin/rails:3:in load'
20: from /home/kaishi/taskleaf/bin/spring:15:in <top (required)>'
19: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in require'
18: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in require'
17: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/spring-2.1.0/lib/spring/binstub.rb:11:in <top (required)>'
16: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/spring-2.1.0/lib/spring/binstub.rb:11:in load'
15: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/spring-2.1.0/bin/spring:49:in <top (required)>'
14: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/spring-2.1.0/lib/spring/client.rb:30:in run'
13: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/spring-2.1.0/lib/spring/client/command.rb:7:in call'
12: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in call'
11: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in load'
10: from /home/kaishi/taskleaf/bin/rails:8:in <top (required)>'
9: from /home/kaishi/taskleaf/bin/rails:8:in require_relative'
8: from /home/kaishi/taskleaf/config/boot.rb:3:in <top (required)>'
7: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in require'
6: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in require'
5: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/bundler-2.0.2/lib/bundler/setup.rb:9:in <top (required)>'
4: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/bundler-2.0.2/lib/bundler/setup.rb:12:in rescue in <top (required)>'
3: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/bundler-2.0.2/lib/bundler/setup.rb:12:in message'
2: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/bundler-2.0.2/lib/bundler/dsl.rb:574:in to_s'
1: from /home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/bundler-2.0.2/lib/bundler/dsl.rb:544:in contents'
/home/kaishi/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/bundler-2.0.2/lib/bundler/dsl.rb:544:in `read': Permission denied @ rb_sysopen - /home/kaishi/taskleaf/Gemfile (Errno::EACCES)

###該当のソースコード
bin/rails s

###試したこと1
Gemfileの権限がない可能性があるとのことなので、
sudo chmod 666 Gemfile
sudo chmod 666 Gemfile.lock
を実行し、同じくbin/rails sを実行すると、以下のようになりました。

###発生している問題・エラーメッセージ2

=> Booting Puma
=> Rails 5.2.3 application starting in development
=> Run rails server -h for more startup options
Exiting
Traceback (most recent call last):
84: from bin/rails:3:in <main>' 83: from bin/rails:3:in load'
82: from /home/kaishi/taskleaf/bin/spring:15:in `<top (required)>'

~~長いので省略~~

   1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:54:in `load': cannot load such file -- /home/kaishi/taskleaf/config/initializers/locale.rb (LoadError)