$ sudo gem install building
Successfully installed building-1.1.2
Parsing documentation for building-1.1.2
Done installing documentation for building after 0 seconds
1 gem installed
$ building
/usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in require': cannot load such file -- highline/import (LoadError) from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:inrequire'
from /home/ec2-user/.gem/ruby/2.0/gems/building-1.1.2/lib/building.rb:4:in <top (required)>' from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:inrequire'
from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in require' from /home/ec2-user/.gem/ruby/2.0/gems/building-1.1.2/bin/building:3:in<top (required)>'
from /usr/local/bin/building:23:in load' from /usr/local/bin/building:23:in
'
$ sudo gem install building
'Successfully installed building-1.1.2
Parsing documentation for building-1.1.2
Done installing documentation for building after 0 seconds
1 gem installed
$ building
/usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in
require': cannot load such file -- highline/import (LoadError) from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:inrequire'from /home/ec2-user/.gem/ruby/2.0/gems/building-1.1.2/lib/building.rb:4:in
<top (required)>' from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:inrequire'from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in
require' from /home/ec2-user/.gem/ruby/2.0/gems/building-1.1.2/bin/building:3:in<top (required)>'from /usr/local/bin/building:23:in
load' from /usr/local/bin/building:23:in