installation errors

[iu43rh43]

Any idea what i can do differently? Using ubuntu 16.04 and everything is upto date in its latest version.

$ cd ~/Downloads/darcli-gh-pages/

$ bundle install

Fetching gem metadata from https://rubygems.org/............
Fetching version metadata from https://rubygems.org/...
Fetching dependency metadata from https://rubygems.org/..
Resolving dependencies...
Using i18n 0.7.0
Using json 1.8.3
Using minitest 5.9.0
Using thread_safe 0.3.5
Using addressable 2.4.0
Using coffee-script-source 1.10.0
Using execjs 2.7.0
Using colorator 1.1.0
sudo: unable to resolve host pc
Installing ffi 1.9.14 with native extensions

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

current directory: /tmp/bundler20160828-3852-1q1quhsffi-1.9.14/gems/ffi-1.9.14/ext/ffi_c
/usr/bin/ruby2.3 -r ./siteconf20160828-3852-s8ojmx.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /tmp/bundler20160828-3852-1q1quhsffi-1.9.14/gems/ffi-1.9.14 for inspection.
Results logged to /tmp/bundler20160828-3852-1q1quhsffi-1.9.14/extensions/x86_64-linux/2.3.0/ffi-1.9.14/gem_make.out
Using multipart-post 2.0.0
Using forwardable-extended 2.6.0
Using gemoji 2.1.0
Using net-dns 0.8.0
Using public_suffix 1.5.3
Using sass 3.4.22
Using rb-fsevent 0.9.7
Using kramdown 1.11.1
Using liquid 3.0.6
Using mercenary 0.3.6
Using rouge 1.11.1
Using safe_yaml 1.0.4
Using jekyll-feed 0.5.1
Using mini_portile2 2.1.0
Using pkg-config 1.1.7
Using jekyll-paginate 1.1.0
Using jekyll-sitemap 0.10.0
Using minima 1.0.1
Using terminal-table 1.6.0
Using bundler 1.11.2
Using tzinfo 1.2.2
Using coffee-script 2.4.1
An error occurred while installing ffi (1.9.14), and Bundler cannot continue.
Make sure that 'gem install ffi -v '1.9.14' succeeds before bundling.

$ sudo gem install ffi -v '1.9.14'

Building native extensions. This could take a while...
ERROR: Error installing ffi:
ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.3.0/gems/ffi-1.9.14/ext/ffi_c
/usr/bin/ruby2.3 -r ./siteconf20160828-3733-1y2bri7.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.3.0/gems/ffi-1.9.14 for inspection.
Results logged to /var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/ffi-1.9.14/gem_make.out

$ cat /var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/ffi-1.9.14/gem_make.out

current directory: /var/lib/gems/2.3.0/gems/ffi-1.9.14/ext/ffi_c
/usr/bin/ruby2.3 -r ./siteconf20160828-3869-1wg6zbm.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

$ sudo gem install ffi

Building native extensions. This could take a while...
ERROR: Error installing ffi:
ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.3.0/gems/ffi-1.9.14/ext/ffi_c
/usr/bin/ruby2.3 -r ./siteconf20160828-4611-fq3a7h.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

$ sudo gem install github-pages

Successfully installed listen-3.0.6
Fetching: pathutil-0.14.0.gem (100%)
Successfully installed pathutil-0.14.0
Fetching: jekyll-3.2.1.gem (100%)
Successfully installed jekyll-3.2.1
Fetching: ethon-0.9.0.gem (100%)
Successfully installed ethon-0.9.0
Fetching: typhoeus-0.8.0.gem (100%)
Successfully installed typhoeus-0.8.0
Fetching: faraday-0.9.2.gem (100%)
Successfully installed faraday-0.9.2
Fetching: sawyer-0.7.0.gem (100%)
Successfully installed sawyer-0.7.0
Fetching: octokit-4.3.0.gem (100%)
Successfully installed octokit-4.3.0
Fetching: github-pages-health-check-1.2.0.gem (100%)
Successfully installed github-pages-health-check-1.2.0
Fetching: nokogiri-1.6.8.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing github-pages:
ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.3.0/gems/nokogiri-1.6.8/ext/nokogiri
/usr/bin/ruby2.3 -r ./siteconf20160828-3890-sbw0ti.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

[gildasio]

So, cause this and more that I don't like gem :|

@HeadlessChild , have any idea about this?