How to Solve problem of wpscan in Backtrack 5 r3?

Wpscan is wordpress security scanner, which is pre-installed in backtrack 5 , but it`s outdated version, so when you tried to update it, you may  have face some problems. Here is solution which work for me.

cd /pentest/web
rm -rf wpscan
git clone https://github.com/wpscanteam/wpscan.git
cd wpscan

gem install bundler && bundle install --without test development
apt-get install libxml2 libxml2-dev libxslt1-dev
gem install  bundler

bundle install

ruby ./wpscan.rb

==WPSCAN ARGUMENTS==

--update   Update to the latest revision

--url   | -u <target url>  The WordPress URL/domain to scan.

--force | -f Forces WPScan to not check if the remote site is running WordPress.

--enumerate | -e [option(s)]  Enumeration.
  option :
    u        usernames from id 1 to 10
    u[10-20] usernames from id 10 to 20 (you must write [] chars)
    p        plugins
    vp       only vulnerable plugins
    ap       all plugins (can take a long time)
    tt       timthumbs
    t        themes
    vp       only vulnerable themes
    at       all themes (can take a long time)
  Multiple values are allowed : '-e tt,p' will enumerate timthumbs and plugins
  If no option is supplied, the default is 'vt,tt,u,vp'

--exclude-content-based '<regexp or string>'  Used with the enumeration option, will exclude all occurrences based on the regexp or string supplied
                                              You do not need to provide the regexp delimiters, but you must write the quotes (simple or double)

--config-file | -c <config file> Use the specified config file

--follow-redirection  If the target url has a redirection, it will be followed without asking if you wanted to do so or not

--wp-content-dir <wp content dir>  WPScan try to find the content directory (ie wp-content) by scanning the index page, however you can specified it. Subdirectories are allowed

--wp-plugins-dir <wp plugins dir>  Same thing than --wp-content-dir but for the plugins directory. If not supplied, WPScan will use wp-content-dir/plugins. Subdirectories are allowed

--proxy <[protocol://]host:port>  Supply a proxy (will override the one from conf/browser.conf.json).
                                  HTTP, SOCKS4 SOCKS4A and SOCKS5 are supported. If no protocol is given (format host:port), HTTP will be used

--proxy-auth <username:password>  Supply the proxy login credentials (will override the one from conf/browser.conf.json).

--basic-auth <username:password>  Set the HTTP Basic authentication

--wordlist | -w <wordlist>  Supply a wordlist for the password bruter and do the brute.

--threads  | -t <number of threads>  The number of threads to use when multi-threading requests. (will override the value from conf/browser.conf.json)

--username | -U <username>  Only brute force the supplied username.

--help     | -h This help screen.

--verbose  | -v Verbose output.

==WPSCAN EXAMPLES==

Do 'non-intrusive' checks...

  ruby wpscan.rb --url www.example.com

Do wordlist password brute force on enumerated users using 50 threads...

  ruby wpscan.rb --url www.example.com --wordlist darkc0de.lst --threads 50

Do wordlist password brute force on the 'admin' username only...

  ruby wpscan.rb --url www.example.com --wordlist darkc0de.lst --username admin

Enumerate installed plugins...

  ruby wpscan.rb --url www.example.com --enumerate p

==WPSTOOLS ARGUMENTS==

--help    | -h   This help screen.
--Verbose | -v   Verbose output.
--update  | -u   Update to the latest revision.
--generate_plugin_list [number of pages]  Generate a new data/plugins.txt file. (supply number of *pages* to parse, default : 150)
--gpl  Alias for --generate_plugin_list
--check-local-vulnerable-files | --clvf <local directory>  Perform a recursive scan in the <local directory> to find vulnerable files or shells

==WPSTOOLS EXAMPLES==

- Generate a new 'most popular' plugin list, up to 150 pages ...
ruby wpstools.rb --generate_plugin_list 150

- Locally scan a wordpress installation for vulnerable files or shells :
ruby wpstools.rb --check-local-vulnerable-files /var/www/wordpress/

 If this solution does not work for you then try to upgrade ruby version & then process to installation.