LoadError: no such file to load -- mechanize

Problem

root@khojguru:~# irb
irb(main):001:0> require 'mechanize'
LoadError: no such file to load -- mechanize
        from (irb):1:in `require'
        from (irb):1

Cause

Because the of versioned nature of the gems repository, RubyGems doesn’t store the library files directly in standard library search path. It adds the necessary gem packages to the library search path as needed at run time.
This means that RubyGems must be loaded before any gem libraries are accessable.

Solution

Add this

export RUBYOPT=rubygems

to

~/.bashrc

Reload

To reload the changes you need to fire...

root@khojguru:~#source ~/.bashrc

Check it out

irb(main):003:0> require 'mechanize'
=> true