Spring Rspec binstub does not improve speed with Rails 5 RC1

Question

I am using Rails 5 RC1. With spring-commands-rspec gem (which was not updated for a while at the time of writing), I created this spring rspec binstub in bin/rspec :

 #!/usr/bin/env ruby begin load File.expand_path('../spring', __FILE__) rescue LoadError => e raise unless e.message.include?('spring') end require_relative '../config/boot' load Gem.bin_path('rspec-core', 'rspec') 

bin/rspec works, but if I run bin/rspec , it will take as long as the first time.

There is no speed improvement, although spring status shows me this:

 Spring is running: 29530 spring server | my_app | started 9 secs ago 29531 spring app | my_app | started 9 secs ago | test mode 

which assumes everything is preloaded correctly.

The same setup works fine on Rails 4. Any idea on how to make it work in Rails 5 RC1?