wsl_ubuntu_unixsocket_error.rb

#!/usr/bin/env ruby

# This script establishes a UNIX server socket.
# 
# Expected result: Script should run and immediately exit.
# 
# Actual result: Script fails with Errno::EADDRINUSE error.
# 
# Environment: Windows 10 Pro, WSL, Ubuntu 18.04.2, ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-linux-gnu]
# 
# To reproduce: Create a tmp folder, copy this script there, and execute.

require 'socket'

path = File.expand_path('listen.sock')
backlog = 5

s = UNIXServer.new(path)
if backlog
  s.listen backlog
else
  s.listen
end

File.delete(path) if File.exists?(path)