I just got into rails programming and it looks like there are two programs I can use to run my project locally: rackup and foreman.
One difference I noticed is that foreman will not output some things that I would expect to see and I would see if I ran rackup instead, until I press ctrl+c to close the server. Then all those messages appear, as if they were being hidden.
Is there a reason for this? How can I get foreman to be more verbose?
If you are not seeing any output from your program, there is a likely chance that it is buffering stdout. Ruby buffers stdout by default.
you can fix this by putting the following code in your development.rb file:
$stdout.sync = true
来源：https://stackoverflow.com/questions/9953435/why-does-foreman-not-output-some-things-until-i-press-control-c