Installing the 'vagrant-managed-servers' plugin. This can take a few minutes...
/usr/lib/ruby/2.3.0/rubygems/specification.rb:946:in all=': undefined methodgroup_by' for nil:NilClass (NoMethodError)
from /usr/lib/ruby/vendor_ruby/vagrant/bundler.rb:275:in with_isolated_gem' from /usr/lib/ruby/vendor_ruby/vagrant/bundler.rb:231:ininternal_install'
from /usr/lib/ruby/vendor_ruby/vagrant/bundler.rb:102:in install' from /usr/lib/ruby/vendor_ruby/vagrant/plugin/manager.rb:62:inblock in install_plugin'
from /usr/lib/ruby/vendor_ruby/vagrant/plugin/manager.rb:72:in install_plugin' from /usr/share/vagrant/plugins/commands/plugin/action/install_gem.rb:37:incall'
from /usr/lib/ruby/vendor_ruby/vagrant/action/warden.rb:34:in call' from /usr/lib/ruby/vendor_ruby/vagrant/action/builder.rb:116:incall'
from /usr/lib/ruby/vendor_ruby/vagrant/action/runner.rb:66:in block in run' from /usr/lib/ruby/vendor_ruby/vagrant/util/busy.rb:19:inbusy'
from /usr/lib/ruby/vendor_ruby/vagrant/action/runner.rb:66:in run' from /usr/share/vagrant/plugins/commands/plugin/command/base.rb:14:inaction'
from /usr/share/vagrant/plugins/commands/plugin/command/install.rb:32:in block in execute' from /usr/share/vagrant/plugins/commands/plugin/command/install.rb:31:ineach'
from /usr/share/vagrant/plugins/commands/plugin/command/install.rb:31:in execute' from /usr/share/vagrant/plugins/commands/plugin/command/root.rb:56:inexecute'
from /usr/lib/ruby/vendor_ruby/vagrant/cli.rb:42:in execute' from /usr/lib/ruby/vendor_ruby/vagrant/environment.rb:268:incli'
from /usr/bin/vagrant:173:in `'
vagrant plugin install vagrant-managed-servers
Installing the 'vagrant-managed-servers' plugin. This can take a few minutes... /usr/lib/ruby/2.3.0/rubygems/specification.rb:946:in'
all=': undefined method
group_by' for nil:NilClass (NoMethodError) from /usr/lib/ruby/vendor_ruby/vagrant/bundler.rb:275:inwith_isolated_gem' from /usr/lib/ruby/vendor_ruby/vagrant/bundler.rb:231:in
internal_install' from /usr/lib/ruby/vendor_ruby/vagrant/bundler.rb:102:ininstall' from /usr/lib/ruby/vendor_ruby/vagrant/plugin/manager.rb:62:in
block in install_plugin' from /usr/lib/ruby/vendor_ruby/vagrant/plugin/manager.rb:72:ininstall_plugin' from /usr/share/vagrant/plugins/commands/plugin/action/install_gem.rb:37:in
call' from /usr/lib/ruby/vendor_ruby/vagrant/action/warden.rb:34:incall' from /usr/lib/ruby/vendor_ruby/vagrant/action/builder.rb:116:in
call' from /usr/lib/ruby/vendor_ruby/vagrant/action/runner.rb:66:inblock in run' from /usr/lib/ruby/vendor_ruby/vagrant/util/busy.rb:19:in
busy' from /usr/lib/ruby/vendor_ruby/vagrant/action/runner.rb:66:inrun' from /usr/share/vagrant/plugins/commands/plugin/command/base.rb:14:in
action' from /usr/share/vagrant/plugins/commands/plugin/command/install.rb:32:inblock in execute' from /usr/share/vagrant/plugins/commands/plugin/command/install.rb:31:in
each' from /usr/share/vagrant/plugins/commands/plugin/command/install.rb:31:inexecute' from /usr/share/vagrant/plugins/commands/plugin/command/root.rb:56:in
execute' from /usr/lib/ruby/vendor_ruby/vagrant/cli.rb:42:inexecute' from /usr/lib/ruby/vendor_ruby/vagrant/environment.rb:268:in
cli' from /usr/bin/vagrant:173:in `Ubuntu 16.04, php 7