Installing fog – unable to convert from ASCII-8BIT to UTF-8-Collection of common programming errors

I am needing to install fog to use SDK to interface with openstack and create a plugin. So far I’m failing at the first step. I am looking for any advice on how I could debug these errors and any opinion on whether the install is okay with them still there.

gem install fog
Fetching: builder-3.2.2.gem (100%)
Successfully installed builder-3.2.2
Fetching: excon-0.28.0.gem (100%)
Successfully installed excon-0.28.0
Fetching: formatador-0.2.4.gem (100%)
Successfully installed formatador-0.2.4
Fetching: multi_json-1.8.2.gem (100%)
Successfully installed multi_json-1.8.2
Fetching: mime-types-2.0.gem (100%)
Successfully installed mime-types-2.0
Fetching: net-scp-1.1.2.gem (100%)
Successfully installed net-scp-1.1.2
Fetching: mini_portile-0.5.2.gem (100%)
Successfully installed mini_portile-0.5.2
Fetching: nokogiri-1.6.0.gem (100%)
Building native extensions.  This could take a while...
Successfully installed nokogiri-1.6.0
Fetching: ruby-hmac-0.4.0.gem (100%)
Successfully installed ruby-hmac-0.4.0
Fetching: fog-1.18.0.gem (100%)
Successfully installed fog-1.18.0
Installing ri documentation for builder-3.2.2
Installing ri documentation for excon-0.28.0
Installing ri documentation for fog-1.18.0
Installing ri documentation for formatador-0.2.4
Installing ri documentation for mime-types-2.0
Installing ri documentation for mini_portile-0.5.2
Installing ri documentation for multi_json-1.8.2
Installing ri documentation for net-scp-1.1.2
unable to convert "\xE4" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxml2/2.8.0/libxml2-2.8.0/doc/examples/testWriter.c, skipping
unable to convert "\xF8" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxml2/2.8.0/libxml2-2.8.0/entities.c, skipping
unable to convert "\xE9" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxml2/2.8.0/libxml2-2.8.0/runtest.c, skipping
unable to convert "\xC0" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxml2/2.8.0/libxml2-2.8.0/test/XInclude/ents/isolatin.txt, skipping
unable to convert "\xF8" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxml2/2.8.0/libxml2-2.8.0/testapi.c, skipping
unable to convert "\xF6" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxslt/1.1.26/libxslt-1.1.26/ChangeLog, skipping
unable to convert "\xF6" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxslt/1.1.26/libxslt-1.1.26/libxslt/xslt.c, skipping
unable to convert "\xE1" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxslt/1.1.26/libxslt-1.1.26/NEWS, skipping
unable to convert "\x89" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxslt/1.1.26/libxslt-1.1.26/tests/xmlspec/logo-REC, skipping
unable to convert "\xFD" from ASCII-8BIT to UTF-8 for ext/nokogiri/tmp/x86_64-apple-darwin12.4.0/ports/libxslt/1.1.26/libxslt-1.1.26/win32/Readme.txt, skipping
unable to convert "\xCF" from ASCII-8BIT to UTF-8 for ports/x86_64-apple-darwin12.4.0/libxml2/2.8.0/bin/xmlcatalog, skipping
unable to convert "\xCF" from ASCII-8BIT to UTF-8 for ports/x86_64-apple-darwin12.4.0/libxml2/2.8.0/bin/xmllint, skipping
unable to convert "\xCF" from ASCII-8BIT to UTF-8 for ports/x86_64-apple-darwin12.4.0/libxslt/1.1.26/bin/xsltproc, skipping
Installing ri documentation for nokogiri-1.6.0
Installing ri documentation for ruby-hmac-0.4.0
10 gems installed

For some reason I am getting the above error. Is there anything I can do to fix this?