DEV: disable async logging in development on broken Ruby

Ruby 2.5.3 has an upatched issue that crashes unicorn after fork:

https://bugs.ruby-lang.org/issues/14634

This will be patched in 2.5.4 however for now just warn people dev is slower
and disable async logging on the older rubies

Gemfile.lock

@@ -186,7 +186,7 @@ GEM
     logstash-event (1.2.02)
     logstash-logger (0.26.1)
       logstash-event (~> 1.2)
-    logster (2.1.0)
+    logster (2.1.1)
     loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)

config/initializers/100-logster.rb

@@ -1,3 +1,12 @@
+if Rails.env.development? && RUBY_VERSION.match?(/^2\.5\.[23]/)
+  STDERR.puts "WARNING: Discourse development environment runs slower on Ruby 2.5.3 or below"
+  STDERR.puts "We recommend you upgrade to Ruby 2.6.1 for the optimal development performance"
+
+  # we have to used to older and slower version of the logger cause the new one exposes a Ruby bug in
+  # the Queue class which causes segmentation faults
+  Logster::Scheduler.disable
+end
+
 if Rails.env.development? && !Sidekiq.server? && ENV["RAILS_LOGS_STDOUT"] == "1"
   console = ActiveSupport::Logger.new(STDOUT)
   original_logger = Rails.logger.chained.first