Navid Shafie said about 5 years ago on puma-dev replacement for pow and prax :
I ran tail -f ~/library/Logs/puma-dev.log and this is the output: * HTTPS Server port: inherited from launchd ! Puma dev listening on http and https and bunch of 2018/12/28 20:25:21 Error listening: accept tcp 0.0.0.0:0: accept: invalid argument * Directory for apps: /Users/UserName/.puma-dev * Domains: test * DNS Server port: 9253 * HTTP Server port: inherited from launchd * HTTPS Server port: inherited from launchd ! Puma dev listening on http and https 2018/12/28 20:25:31 Error listening: accept tcp 0.0.0.0:0: accept: invalid argument