Bundle install attempt

gistfile1.txt

$ sudo bundle install
Fetching gem metadata from https://rubygems.org/........
Fetching additional metadata from https://rubygems.org/..
Using archive-tar-minitar (0.5.2)

Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

        /usr/bin/ruby1.9.1 extconf.rb
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError)
	from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
	from extconf.rb:4:in `<main>'


Gem files will remain installed in /var/lib/gems/1.9.1/gems/ffi-1.9.3 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/ffi-1.9.3/ext/ffi_c/gem_make.out
An error occurred while installing ffi (1.9.3), and Bundler cannot continue.
Make sure that `gem install ffi -v '1.9.3'` succeeds before bundling.