seems that its just not compilable:
src/main/java/org/jruby/RubyFile.java:[1532,28] error: no suitable method found for newFileStat(String)

@maclover7 @kares Amazingly someone else had submitted a PR before you and I landed it but perhaps a single stat is better than an exist? + stat() hmm. exist? on java.io.File is quicker than us performing a stat via jnr-posix but I am guessing more than half the time you expect the file to exist so you are doing two things...

The other PR probably works better on a minutes reflection as this mechanism will raise an ENOENT or ENODIR I think if the file does not actually exist in stat.setup().

@kcdragon @maclover7 what would work and if either of you are up for it would be to do something like:

file = JRubyFile.createResource(runtime, filename);
if file == null then 
  false
else 
  file.stat.exist?
end

We try really hard to avoid exception when we can as they are expensive. This above approach will eliminate the original exist() + stat() calling on existing file (which is two stat() calls) to a single one.

Open a new PR if either of you want to take that on. I am closing this one.