以前这很正常，但是当我重新打开wpscan时更新了许多软件包之后，便发生了
当我运行wpscan时，输出将如下所示：
Traceback (most recent call last):
20: from /usr/bin/wpscan:23:in `<main>'
19: from /usr/lib/ruby/2.5.0/rubygems.rb:309:in `activate_bin_path'
18: from /usr/lib/ruby/2.5.0/rubygems.rb:309:in `synchronize'
17: from /usr/lib/ruby/2.5.0/rubygems.rb:310:in `block in activate_bin_path'
16: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1440:in `activate'
15: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `activate_dependencies'
14: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `each'
13: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1472:in `block in activate_dependencies'
12: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1440:in `activate'
11: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `activate_dependencies'
10: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1458:in `each'
9: from /usr/lib/ruby/2.5.0/rubygems/specification.rb:1472:in `block in activate_dependencies'
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:310:in `to_specs': Could not find 'ffi' (>= 1.3.0) among 121 total gem(s) (Gem::MissingSpecError)
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
我该如何解决？