When I call
FileUtils.mkdir_p("//Server/share/my_new_directory")
it raise the Errno::ENOENT: No such file or directory - \Server
This code worked perfectly in MRI.
Otherwise loving JRuby...
additional info:
jruby 1.7.12 (1.9.3p392) 2014-04-15 643e292 on Java HotSpot(TM) 64-Bit Server VM 1.8.0-b132 +indy [Windows 7-amd64]