Setting RACK_ENV makes no sense

[leshik]

Setting RACK_ENV to values other than development, deployment, or none makes no sense, as per rackup howto. Setting it to production or test is equal to setting it to none (disabling logging middleware), so it's not the RAILS_ENV replacement for rack apps.
Here are some explanations.
I'm not sure how this should be addressed, maybe using the different env var would be better.