rack#b2d73960e9ea6b8b15321ef190f13a290d1aedf0 introduces the relevant change -
In previous versions, request.rack_request.dup.env was still the same object
as request.rack_request.env and so updates to it did update the original
rack env, which appears to be behavior that we're depending on elsewhere.
Given that we'll often want to update the env (see e.g. hanami/controller's
handling of env['hanami.action']), I'm struggling to understand why the
dup was there in the first place. But in any case, this gets the tests
back passing on Rack '~> 2.0'.
rack#b2d73960e9ea6b8b15321ef190f13a290d1aedf0 introduces the relevant change - In previous versions,
request.rack_request.dup.envwas still the same object asrequest.rack_request.envand so updates to it did update the original rack env, which appears to be behavior that we're depending on elsewhere.Given that we'll often want to update the env (see e.g. hanami/controller's handling of
env['hanami.action']), I'm struggling to understand why thedupwas there in the first place. But in any case, this gets the tests back passing on Rack '~> 2.0'.