ruby - Rails 5 Address already in use - bind(2) for "127.0.0.1" port 3000 -

after coding got error on running rails s:

address in use - bind(2) "127.0.0.1" port 3000 (errno::eaddrinuse) 

my environment is:

$ rails -v        rails 5.0.0 $ ruby -v ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux] 

i've tried:

1. create new project - same
2. checked rails 4.2 - problem solved
3. reinstall rails 5 , ruby - same problem
4. lsof -wni tcp:3000 returns me nothing
5. ps aux | grep "rails" - nothing
6. ps aux | grep "puma" - nothing
7. ps aux | grep "ruby" -nothing
8. use puma instead of rails s - problem solved
9. use rails s -p 3001 - same problem, other ports too

updated

9. use rails_env=production bundle exec rails s - problem solved

any suggestions?

the problem appeared because of bug in puma's code. downgrading oldest version helped me.

bug ticket: https://github.com/puma/puma/issues/1022