output.txt

❯ make runruby
./miniruby -I./lib -I. -I.ext/common  ./tool/runruby.rb --extout=.ext  -- --disable-gems ./test.rb
<internal:ractor>:38: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues.
#<Thread:0x00007fadd701fa90 run> terminated with exception (report_on_exception is true):
<internal:ractor>:124:in `take': thrown by remote Ractor. (Ractor::RemoteError)
	from ./test.rb:11:in `<main>'
./test.rb:5:in `logger': can not access instance variables of classes/modules from non-main Ractors (RuntimeError)
	from ./test.rb:10:in `block in <main>'
make: *** [runruby] Error 1

test.rb

require 'logger'

class Rails
  def self.logger
    @logger ||= Logger.new(STDOUT)
  end
end

Ractor.new do
  Rails.logger.info "Hello"
end.take