2.3.0 :001 > require 'pty'
 => true 
2.3.0 :002 > PTY.open{|m,s|}
 => nil 

jruby-9.1.15.0 :001 > require 'pty'
 => true 
jruby-9.1.15.0 :002 > PTY.open{|m,s|}
NotImplementedError: F_SETFL only supports O_NONBLOCK
	from org/jruby/RubyIO.java:2441:in `fcntl'
	from /home/byteit101/.rvm/rubies/jruby-9.1.15.0/lib/ruby/stdlib/pty.rb:140:in `hack_close_on_exec'
	from /home/byteit101/.rvm/rubies/jruby-9.1.15.0/lib/ruby/stdlib/pty.rb:57:in `block in open'
	from org/jruby/RubyArray.java:1735:in `each'
	from /home/byteit101/.rvm/rubies/jruby-9.1.15.0/lib/ruby/stdlib/pty.rb:54:in `open'
	from (irb):2:in `<eval>'
	from org/jruby/RubyKernel.java:994:in `eval'
	from org/jruby/RubyKernel.java:1292:in `loop'
	from org/jruby/RubyKernel.java:1114:in `catch'
	from org/jruby/RubyKernel.java:1114:in `catch'
	from /home/byteit101/.rvm/rubies/jruby-9.1.15.0/bin/irb:13:in `<main>'