Beef-Xss throws a bunch of errors after trying to update to latest version which is 4.4.8 Alpha
here is what i do
rm -rf /usr/share/beef-xss && git clone https://github.com/beefproject/beef.git /usr/share/beef-xss
gem install bundler
Successfully installed bundler-1.3.5
1 gem installed
Installing ri documentation for bundler-1.3.5...
Installing RDoc documentation for bundler-1.3.5...
Bundle install
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/do_sqlite3-0.10.13 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/do_sqlite3-0.10.13/ext/do_sqlite3/gem_make.out

An error occurred while installing do_sqlite3 (0.10.13), and Bundler cannot
continue.
Make sure that `gem install do_sqlite3 -v '0.10.13'` succeeds before bundling.
Then I do
gem install do_sqlite3 -v '0.10.13'
Building native extensions. This could take a while...
ERROR: Error installing do_sqlite3:
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/do_sqlite3-0.10.13 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/do_sqlite3-0.10.13/ext/do_sqlite3/gem_make.out

-Any Help Apprecated Thanks