Rails refuse to generate new controller

Hi everyone and thanks for the great work. I have a problem with rails : I created a fresh app nicely running on port 3000. I'm trying to reate a nw controller using "rails generate controller Welcome index" and rails is throwing this :

Ignoring bindex-0.5.0 because its extensions are not built.  Try: gem pristine bindex --version 0.5.0
/usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/spec_set.rb:87:in `block in materialize': Could not find nokogiri-1.8.0 in any of the sources (Bundler::GemNotFound)
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/spec_set.rb:81:in `map!'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/spec_set.rb:81:in `materialize'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/definition.rb:159:in `specs'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/definition.rb:218:in `specs_for'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/definition.rb:207:in `requested_specs'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/runtime.rb:109:in `block in definition_method'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/runtime.rb:21:in `setup'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler.rb:101:in `setup'
        from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/setup.rb:20:in `<top (required)>'
        from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/commands.rb:33:in `<module:Spring>'
        from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/commands.rb:4:in `<top (required)>'
        from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/server.rb:9:in `<top (required)>'
        from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/client/server.rb:9:in `call'
        from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/client/command.rb:7:in `call'
        from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/client.rb:30:in `run'
        from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/bin/spring:49:in `<main>'

Does someone have an idea of what this could be ? I cannot figure it out and I will appreciate any help. My OS is opensuse tumbleweed.

Thanks.