Java exceptions on too many open files in 9k

[iconara]

Besides #2106 where a Ruby exception was raised and a Java stack trace dumped to stdout/err there seems to be cases when Java exceptions are not handled and are delivered to the Ruby code:

The full stack traces are here: https://gist.github.com/iconara/95642ed9ce8ff2aaa98b#file-output2

Here's the first few lines:

  2) (Test description here)
     Failure/Error: Unable to find matching line from backtrace
     Java::JavaLang::RuntimeException:
       Unhandled IOException
     # org.jruby.util.io.PosixShim.open(PosixShim.java:418)
     # org.jruby.util.io.PosixShim.open(PosixShim.java:392)
     # org.jruby.RubyIO.cloexecOpen(RubyIO.java:1202)
     # org.jruby.RubyIO.sysopenFunc(RubyIO.java:1188)
     # org.jruby.RubyIO.sysopenInternal(RubyIO.java:1180)
     # org.jruby.RubyIO.sysopen(RubyIO.java:1158)
     # org.jruby.RubyFile.fileOpenGeneric(RubyFile.java:1192)
     # org.jruby.RubyFile.openFile(RubyFile.java:1170)
     # org.jruby.RubyFile.initialize(RubyFile.java:328)
     # org.jruby.RubyFile$INVOKER$i$0$2$initialize.call(RubyFile$INVOKER$i$0$2$initialize.gen)
     # org.jruby.runtime.callsite.CachingCallSite.callBlock(CachingCallSite.java:77)
     # org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:83)
     # org.jruby.RubyClass.newInstance(RubyClass.java:869)
     # org.jruby.RubyIO.open(RubyIO.java:1072)
     # org.jruby.RubyIO$INVOKER$s$0$0$open.call(RubyIO$INVOKER$s$0$0$open.gen)

[headius]

Ahh, good, this I can deal with. We have logic that turns IOException into the appropriate kind of Ruby error, but because Java only gives us a string message to indicate what happened we have some gaps in the translation. Will investigate.