Address ruby warnings:

./lib/rspec/core/example.rb:225: warning: method redefined; discarding old inspect
./lib/rspec/core/example.rb:210: warning: previous definition of inspect was here
A sub-shell is not necessary. It's a new process, just in the same shell session. You still get a new process id. I created a gist with a simple script showing this: https://gist.github.com/cupakromer/950be0f9e5527eeab114