Could not open library 'xml2' 'libxml2.so'

Could not open library 'xml2' : xml2: 
cannot open shared object file: No such file or directory. 
Could not open library 'libxml2.so' :
 libxml2.so: cannot open shared object file: No such file or directory 
(LoadError)

To fix the issue, please run the following command:

sudo apt-get install ruby1.8-dev
sudo apt-get install libxml2 libxml2-dev libxslt1-dev