What version is this JRuby?

Ruby JRuby
1

I am trying to debug logstash-2.2.2 in Eclipse, and I cannot figure out
the version of JRuby that came with it. Does below output say 1.7.23, or
1.9.3?

c:\workspace\logstash\vendor\jruby\bin>jruby.exe --version
jruby 1.7.23 (1.9.3p551) 2015-11-24 f496dd5 on Java HotSpot™ 64-Bit
Server VM 1.8.0_73-b02 +jit [Windows 7-amd64]

I am getting compiler errors that may be caused by using JRuby 1.7, but
adding -Xcompat.version=1.9 did not work.

2

JRuby displays two version numbers. The first shows the JRuby version
itself. The second shows the corresponding MRI Ruby version it is based
on (i.e. the implemented language).