It is possible to receive an error after updating wpscan via “svn up” complaining about the nokogiri gem. This might be confusing because likely you already have the nokogiri gem installed on Backtrack Linux however it is likely a simple path issue. To resolve you can issue the below gem install –user-install command as shown in the below example.
While creating a development environment for a Ruby project earlier I ran into an error installing some of the gems required by the project. I realized that I had installed an older version of RubyGems which was causing problems with some of the gem dependents that needed to be installed. Below I list one of the examples of the errors I was running into and how I resolved the issue.
ERROR: Error installing webrat: Could not create Makefile due to some reason, probably lack of necessary libraries and/or headers.
One of my tasks today at work was to install numerous Ruby gems on a couple of our development servers. One of those gems was called webrat which is used for “Ruby acceptance testing and for web applications”. When I attempted to install webrat using “gem install webrat” from a Linux shell I received some errors which I describe below along with how to resolve the error in my scenario. It is likely for you to get similar errors however not the same exact errors so the key is analyzing the output of the “gem install” command to see if it will lead you to resolution.