nexus-cli get_global_settings fails with ruby 1.8

[i11]

$ nexus-cli get_global_settings
/usr/lib/ruby/gems/1.8/gems/jsonpath-0.5.3/lib/jsonpath/enumerable.rb:106: warning: regexp has invalid interval
/usr/lib/ruby/gems/1.8/gems/jsonpath-0.5.3/lib/jsonpath/enumerable.rb:106: warning: regexp has }' without escape /usr/lib/ruby/gems/1.8/gems/nexus_cli-3.0.0/lib/nexus_cli/mixins/global_settings_actions.rb:13:inget_global_settings': undefined method exists?' for Dir:Class (NoMethodError) from /usr/lib/ruby/gems/1.8/gems/nexus_cli-3.0.0/lib/nexus_cli/tasks.rb:104:inget_global_settings'
from /usr/lib/ruby/gems/1.8/gems/thor-0.18.1/lib/thor/command.rb:27:in __send__' from /usr/lib/ruby/gems/1.8/gems/thor-0.18.1/lib/thor/command.rb:27:inrun'
from /usr/lib/ruby/gems/1.8/gems/thor-0.18.1/lib/thor/invocation.rb:120:in invoke_command' from /usr/lib/ruby/gems/1.8/gems/thor-0.18.1/lib/thor.rb:363:indispatch'
from /usr/lib/ruby/gems/1.8/gems/thor-0.18.1/lib/thor/base.rb:439:in start' from /usr/lib/ruby/gems/1.8/gems/nexus_cli-3.0.0/bin/nexus-cli:6 from /usr/bin/nexus-cli:19:inload'
from /usr/bin/nexus-cli:19

$ ruby -v
ruby 1.8.7 (2011-06-30 patchlevel 352) [x86_64-linux]

$ ls -la ~/.nexus
total 8
drwxrwxr-x 2 vagrant vagrant 4096 Jul 11 18:00 .
drwx------. 5 vagrant vagrant 4096 Jul 11 18:01 ..