Hi!

I'm new to Ruby, but I believe, I've stumbled across a bug in JRuby implementation. I prepared a minimal example, which should be self-explanatory, so let me start with that.

Reproducer

reproducer.sh:

#!/bin/sh

cat << EOF > main.rb
Dir.chdir("foo")
require_relative "other"
puts "main finished"
EOF

cat << EOF > other.rb
puts "other finished"
EOF

mkdir -p foo

echo "MRI>"   &&  ruby main.rb
echo "JRuby>" && jruby main.rb

cd /tmp && sh ./reproducer.sh

MRI>
other finished
main finished
JRuby>
Errno::ENOENT: No such file or directory - /tmp/foo/main.rb
          realpath at org/jruby/RubyFile.java:898
  require_relative at org/jruby/RubyKernel.java:1040
            <main> at main.rb:2

Compliance

JRuby's behavior looks non-compliant to me, as language specification requires treating the other.rb path as relative to the requiring file’s path, regardless of the current working directory
https://docs.ruby-lang.org/en/3.1/Kernel.html#method-i-require_relative

Environment Information

I believe, this should be widely reproducible, but here's my setup

$ jruby -v
jruby 9.3.8.0 (2.6.8) 2022-09-13 98d69c9461 OpenJDK 64-Bit Server VM 18.0.2+0 on 18.0.2+0 +jit [x86_64-linux]

Arch Llinux (kernel 5.10.142-1), also reproduced on Ubuntu 18.04, with several versions of jruby (and an older JVM).