Error at rake docs and whitespace

[junaruga]

$ ruby -v
ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-linux]

$ bundle -v
Bundler version 1.14.6

$ bundle install --path vendor/bundle 

$ bundle exec rake whitespace
sed: can't read s/ *$//g: No such file or directory
sed: can't read s/ *$//g: No such file or directory
...

=> I am using Linux. So that is reason? sed command's specification is different?

Then, install hanna that is used in rake docs.

$ echo "gem 'hanna'" >> Gemfile

$ bundle update

$ bundle exec rake docs
bundler: failed to load command: rake (/home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/bin/rake)
NameError: uninitialized constant Rake::AltSystem::Config
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/lib/rake/alt_system.rb:32:in `<module:AltSystem>'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/lib/rake/alt_system.rb:31:in `<top (required)>'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/lib/rake/win32.rb:3:in `require'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/lib/rake/win32.rb:3:in `<module:Rake>'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/lib/rake/win32.rb:2:in `<top (required)>'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/lib/rake.rb:41:in `require'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/lib/rake.rb:41:in `<top (required)>'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/bin/rake:26:in `require'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/gems/rake-0.8.7/bin/rake:26:in `<top (required)>'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/bin/rake:22:in `load'
  /home/jaruga/git/rack-test/vendor/bundle/ruby/2.4.0/bin/rake:22:in `<top (required)>'

[junaruga]

I want to try to fix this after #181 will be merged.