require_relative does not work on windows from inside jars packed by warbler

hello.rb

#./lib/hello.rb
puts "hello world"

main.rb

#./main.rb
require_relative 'hello'

require.gemspec

#./require.gemspec
Gem::Specification.new do |s|
	s.bindir		= '.'
	s.require_paths		= ['lib']
	s.executables		<< 'main.rb'
end

warble.rb

#./config/warble.rb
Warbler::Config.new do |config|
  config.dirs = %w(lib)
end