grey@ibook:~$ sudo gem install jekyll

Fetching: liquid-3.0.6.gem (100%)

Successfully installed liquid-3.0.6

Fetching: kramdown-1.9.0.gem (100%)

Successfully installed kramdown-1.9.0

Fetching: mercenary-0.3.5.gem (100%)

Successfully installed mercenary-0.3.5

Fetching: safe_yaml-1.0.4.gem (100%)

Successfully installed safe_yaml-1.0.4

Fetching: colorator-0.1.gem (100%)

Successfully installed colorator-0.1

Fetching: rouge-1.10.1.gem (100%)

Successfully installed rouge-1.10.1

Fetching: sass-3.4.20.gem (100%)

Successfully installed sass-3.4.20

Fetching: jekyll-sass-converter-1.4.0.gem (100%)

Successfully installed jekyll-sass-converter-1.4.0

Fetching: rb-fsevent-0.9.7.gem (100%)

Successfully installed rb-fsevent-0.9.7

Fetching: ffi-1.9.10.gem (100%)

Building native extensions. This could take a while...

ERROR: Error installing jekyll:

ERROR: Failed to build gem native extension.

/usr/bin/ruby2.1 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/2.1.0/gems/ffi-1.9.10 for inspection.

Results logged to /var/lib/gems/2.1.0/extensions/powerpc-linux/2.1.0/ffi-1.9.10/gem_make.out

grey@ibook:~$ sudo gem install virustotal

Fetching: unf-0.2.0.beta2.gem (100%)

Building native extensions. This could take a while...

ERROR: Error installing virustotal:

ERROR: Failed to build gem native extension.

/usr/bin/ruby2.1 mkrf_conf.rb

Building native extensions. This could take a while...

/usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:89:in `run': ERROR: Failed to build gem native extension. (Gem::Ext::BuildError)

/usr/bin/ruby2.1 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/2.1.0/gems/unf-0.2.0.beta2/ext/gems/gems/unf_ext-0.0.7.1 for inspection.

Results logged to /var/lib/gems/2.1.0/gems/unf-0.2.0.beta2/ext/gems/extensions/powerpc-linux/2.1.0/unf_ext-0.0.7.1/gem_make.out

from /usr/lib/ruby/2.1.0/rubygems/ext/ext_conf_builder.rb:38:in `block in build'

from /usr/lib/ruby/2.1.0/tempfile.rb:324:in `open'

from /usr/lib/ruby/2.1.0/rubygems/ext/ext_conf_builder.rb:17:in `build'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:161:in `block (2 levels) in build_extension'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:160:in `chdir'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:160:in `block in build_extension'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:159:in `synchronize'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:159:in `build_extension'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:198:in `block in build_extensions'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:195:in `each'

from /usr/lib/ruby/2.1.0/rubygems/ext/builder.rb:195:in `build_extensions'

from /usr/lib/ruby/2.1.0/rubygems/installer.rb:677:in `build_extensions'

from /usr/lib/ruby/2.1.0/rubygems/installer.rb:232:in `install'

from /usr/lib/ruby/2.1.0/rubygems/resolver/specification.rb:78:in `install'

from /usr/lib/ruby/2.1.0/rubygems/request_set.rb:206:in `block in install_into'

from /usr/lib/ruby/2.1.0/rubygems/request_set.rb:198:in `each'

from /usr/lib/ruby/2.1.0/rubygems/request_set.rb:198:in `install_into'

from /usr/lib/ruby/2.1.0/rubygems/request_set.rb:119:in `install'

from /usr/lib/ruby/2.1.0/rubygems/dependency_installer.rb:389:in `install'

from mkrf_conf.rb:15:in `<main>'

rake failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.1.0/gems/unf-0.2.0.beta2 for inspection.

Results logged to /var/lib/gems/2.1.0/extensions/powerpc-linux/2.1.0/unf-0.2.0.beta2/gem_make.out