I did this once upon a time, I swear.
RubyMine 2016.3, OSX 10.12.3
Sinatra app. I frequently run rackup from the Run Configurations using the cmd-R shortcut key, and I recall, in years past, there was an IDE option to make that command restart the running app instead of running a new one that fails because the old one was already running.
Can anyone remind me where that checkbox is?