在Kali Linux上執行wpscan的時候，如果出現了以下的錯誤訊息(Error)。
root@HackerCat:~# wpscan -u http://hackercat.org/
Traceback (most recent call last):
12: from /usr/bin/wpscan:23:in `<main>'
11: from /usr/lib/ruby/2.5.0/rubygems.rb:304:in `activate_bin_path'
10: from /usr/lib/ruby/2.5.0/rubygems.rb:304:in `synchronize'
9: from /usr/lib/ruby/2.5.0/rubygems.rb:305:in `block in activate_bin_path'
8: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1440:in `activate'
7: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `activate_dependencies'
6: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `each'
5: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1472:in `block in activate_dependencies'
4: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1440:in `activate'
3: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `activate_dependencies'
2: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `each'
1: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1469:in `block in activate_dependencies'
/usr/lib/ruby/2.5.0/rubygems/dependency.rb:312:in `to_specs': Could not find 'nokogiri' (~> 1.10.8) - did find: [nokogiri-1.10.3] (Gem::MissingSpecVersionError)
Checked in 'GEM_PATH=/root/.gem/ruby/2.5.0:/var/lib/gems/2.5.0:/usr/lib/x86_64-linux-gnu/rubygems-integration/2.5.0:/usr/share/rubygems-integration/2.5.0:/usr/share/rubygems-integration/all', execute `gem env` for more information可以先嘗試利用apt或gem或其他方法安裝nokogiri，
或是利用apt安裝wpscan
或者是到 WPScan Github 將repo給git clone下來嘗試執行看看
https://github.com/wpscanteam/wpscan
如果說還是不行，出現跟最上面一樣的錯誤，
就執行以下兩個指令：
apt-get install ruby-dev libxml2 zlib1g-dev
gem install nokogiri如果真的還是不行，就執行以下的指令：
apt remove wpscan -y
apt-get autoremove -y
apt-get autoclean
hash -r
apt install ruby-dev -y
apt-get install wpscan --reinstall以上這樣應該就可以了，如果還是不行的話，
可能就要再自行多利用關鍵字找找看其他解決方法。