Yes, grep + debugger / pry were how I solved this when I was still writing lots of Ruby. I find it much more productive to be able to get these answers statical

Yes, grep + debugger / pry were how I solved this when I was still writing lots of Ruby. I find it much more productive to be able to get these answers statically, but I was too strong when I said "impossible"; there's always some way to find the right code, or the VM wouldn't be able to run it :)