Not working on Debian / Linux Mint - eventmachine error

[lacostenycoder]

in Gemfile we have

group :development do
  gem 'thin', require: false
end

When I start rails server I get eventmachine errors

rails s -b lvh.me -p 3000
=> Booting Thin
=> Rails 5.2.5 application starting in development on http://lvh.me:3000
=> Run `rails server -h` for more startup options
05/19/2021 9:12AM Thin web server (v1.8.0 codename Possessed Pickle)
05/19/2021 9:12AM Maximum connections set to 1024
05/19/2021 9:12AM Listening on lvh.me:3000, CTRL+C to stop
Exiting
Traceback (most recent call last):
	21: from bin/rails:9:in `<main>'
	20: from bin/rails:9:in `require'
	19: from /home/lance/.gem/ruby/2.6.6/gems/railties-5.2.5/lib/rails/commands.rb:18:in `<top (required)>'
	18: from /home/lance/.gem/ruby/2.6.6/gems/railties-5.2.5/lib/rails/command.rb:46:in `invoke'
	17: from /home/lance/.gem/ruby/2.6.6/gems/railties-5.2.5/lib/rails/command/base.rb:69:in `perform'
	16: from /home/lance/.gem/ruby/2.6.6/gems/thor-0.20.3/lib/thor.rb:387:in `dispatch'
	15: from /home/lance/.gem/ruby/2.6.6/gems/thor-0.20.3/lib/thor/invocation.rb:126:in `invoke_command'
	14: from /home/lance/.gem/ruby/2.6.6/gems/thor-0.20.3/lib/thor/command.rb:27:in `run'
	13: from /home/lance/.gem/ruby/2.6.6/gems/railties-5.2.5/lib/rails/commands/server/server_command.rb:142:in `perform'
	12: from /home/lance/.gem/ruby/2.6.6/gems/railties-5.2.5/lib/rails/commands/server/server_command.rb:142:in `tap'
	11: from /home/lance/.gem/ruby/2.6.6/gems/railties-5.2.5/lib/rails/commands/server/server_command.rb:147:in `block in perform'
	10: from /home/lance/.gem/ruby/2.6.6/gems/railties-5.2.5/lib/rails/commands/server/server_command.rb:53:in `start'
	 9: from /home/lance/.gem/ruby/2.6.6/gems/rack-2.2.3/lib/rack/server.rb:327:in `start'
	 8: from /home/lance/.gem/ruby/2.6.6/gems/thin-1.8.0/lib/rack/handler/thin.rb:22:in `run'
	 7: from /home/lance/.gem/ruby/2.6.6/gems/thin-1.8.0/lib/thin/server.rb:162:in `start'
	 6: from /home/lance/.gem/ruby/2.6.6/gems/thin-1.8.0/lib/thin/backends/base.rb:75:in `start'
	 5: from /home/lance/.gem/ruby/2.6.6/gems/eventmachine-1.2.7/lib/eventmachine.rb:195:in `run'
	 4: from /home/lance/.gem/ruby/2.6.6/gems/eventmachine-1.2.7/lib/eventmachine.rb:195:in `run_machine'
	 3: from /home/lance/.gem/ruby/2.6.6/gems/thin-1.8.0/lib/thin/backends/base.rb:65:in `block in start'
	 2: from /home/lance/.gem/ruby/2.6.6/gems/thin-1.8.0/lib/thin/backends/tcp_server.rb:16:in `connect'
	 1: from /home/lance/.gem/ruby/2.6.6/gems/eventmachine-1.2.7/lib/eventmachine.rb:531:in `start_server'
/home/lance/.gem/ruby/3.6.6/gems/eventmachine-1.2.7/lib/eventmachine.rb:531:in `start_tcp_server': no acceptor (port is in use or requires root privileges) (RuntimeError)

Not sure if this is related to eventmachine/eventmachine#154

I only started to experience this after installing my dependencies in a Linux based setup using Linux Mint 20.1

I tried to see if anything was running on port 3000 and both of there return null

netstat -a | grep 3000
lsof -i :3000         

My only solution was to switch back to rails default webrick server

[ioquatix]

That's a bit weird.

port is in use or requires root privileges

Are you trying to bind twice to the same port?